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  Health and Disease  
  A disease is defined as a condition that disturbs or impairs the normal state of an organism. Diseases can occur in all life forms, and normally affect the functioning of cells, tissues, organs, or systems. Diseases can be classified as infectious or noninfectious. Infectious diseases are caused by microorganisms, such as bacteria and viruses, invading the body; they can be spread across a species, or transmitted between one or more species. All other diseases can be grouped together as noninfectious diseases. These can have many causes, some of which are still unknown today and include such disorders as cardiovascular disease, cancer, and obesity.  
  Some diseases occur mainly in certain climates or geographical regions of the world. These are endemic diseases. For example, African sleeping sickness, which is carried by the tsetse fly, is found mainly in the very hot, humid regions of Africa. Similarly, malaria, a disease spread by mosquitoes, is usually found in or near the marsh or stagnant water which provide breeding grounds for the insect. Other diseases may be seasonal—such as influenza, which tends to occur mainly in winter, or intestinal illnesses that result from food contamination in summer.  
  Some diseases are more common in certain age groups, such as measles in children, meningitis in young adults, and coronary heart disease in the elderly. Other diseases may tend to occur only in certain racial types and are usually genetic in origin, such as sickle-cell disease which is found mainly among people of black African descent.  
  More than three centuries ago most people in the Western world died from infection and the average life expectancy is estimated to have been 30–40 years. Since then the pattern of disease etiology has changed in developed countries, with life expectancy being extended to 70–80 years.  
  While the main causes of death used to include smallpox, tuberculosis, cholera, typhoid, and dysentery, today's mortality statistics in developed countries are dominated by degenerative diseases such as circulatory disorders, and increasingly, neoplastic diseases.  
  In developing countries, where the combined problems of famine, war, and poverty boost the mortality figures, dietary deficiencies and infectious diseases are still the main problems being faced.  
  Infectious Diseases  
  In humans, infections caused by microorganisms (pathogens) are the commonest cause of disease. According to a 1990s World Health Report prepared by the World Health Organization, 17 million deaths (one-third of the total number) occur as a result of infectious diseases. Pathogens are parasites that take over some of the body's cells and tissues, using them for their own growth and reproduction. In the process, the cells and tissues are damaged or destroyed resulting in disease of the host body. These pathogens produce diseases ranging from minor skin infections to  




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The Leading Causes of Mortality in the World
Source: World Resources Institute
Rank Cause
Deaths (thousands)
% of overall deaths
1 Infectious and parasitic diseases
2 Diseases of the circulatory system
3 Other and unknown causes
4 Malignant tumors (neoplasms)
5 Perinatal and neonatal causes
6 Chronic lower respiratory diseases
7 Maternal causes


  life-threatening internal disorders.  
  There are several ways in which pathogens gain access to the body: through the skin, especially through cuts or wounds; through the respiratory system—for instance, cold and influenza viruses are carried through the air in droplets of moisture and are breathed in; in food or water—bacteria causing food poisoning are taken into the alimentary canal in food, poliomyelitis viruses can be transmitted in water; by vectors (organisms that transmit pathogens to host bodies)—such as rabies which is transmitted in the saliva of mammals. (An infected mammal passing on the rabies virus to another is a vector for rabies.)  
  Immense U.S.-based site dealing with all current aspects of medicine in plain language. There is a dictionary of diseases, cures, and medical terms. The site also includes an ''ask the experts" section, lots of current medical news, and last, but not least, some important first aid advice.  
  Infectious diseases can be classified according to the kind of pathogen that causes them. The most common pathogens are bacteria and viruses, but fungi, protozoans, and worms can also cause infectious diseases. Disease-producing protozoans are found chiefly in tropical areas, and cause such diseases as amoebic dysentery, an intestinal infection. Worm infections also cause many serious tropical diseases, including elephantiasis, river blindness, and schistosomiasis.  
  The human body has many natural defenses against the entry of pathogens. For instance, blood clotting can seal a cut or wound thus preventing the entry of pathogens through the skin. The body also has chemical barriers against infection, such as tears, which not only wash foreign substances from the eyes, but also contain enzymes that destroy many common pathogens. In addition, the mucous membranes release protective chemicals. The body's own senses of smell and taste can often detect the presence of bacteria in food before harmful quantities are ingested. Any bacteria that reach the stomach may be killed off by the hydrochloric acid in the stomach's digestive juices. Pathogens that manage to penetrate the body's defenses will be recognized as foreign and come under attack from antibodies produced by the white cells in the blood.  
  During the last century the prevalence of old-style infectious diseases has dramatically been reduced in developed countries. This has been the result of:  
  • improved nutrition and living conditions;  
  • public health measures, such as the introduction of safe water and drainage facilities;  
  • immunization and chemotherapy;  
  Despite these developments, third world countries continue to experience infectious scourges, with acute respiratory infection, gastroenteritis, malaria, and measles being the main cause of early death in children.  
  And the world burden of infection continues. This is due partly to the emergence of "new" infectious diseases, such as acquired immune deficiency syndrome (AIDS), increased international travel means that people are more at risk of tropical diseases such as typhoid, malaria, and schistosomiasis. Additionally, certain infectious organisms have become resistant to drugs. These issues are discussed in the following sections.  
  Acquired Immune Deficiency Syndrome (AIDS)  
  This is the gravest of the sexually transmitted diseases. It is caused by the human immunodeficiency virus (HIV), now known to be a retrovirus, an organism first identified in 1983. HIV is transmitted in body fluids, mainly blood and genital secretions.  




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Mortality, Morbidity, and Disability for Selected Infectious Diseases in the World
Source: World Health Organization
(N/A = not available)
Disease by main mode of transmission
New cases
All cases
Permanent and
long-term affected cases
Person to Person        
Acute lower respiratory infection (ALR)1
Hepatitis B, viral
Whooping cough (pertussis)
Meningococcal meningitis
Poliomyelitis, acute
Syphilis, venereal
Food-, Water-, and Soil-borne        
Neonatonal tetanus
Hookworm diseases
Trematode infections (foodborne only)
Dracunculiasis (guinea-worm infection)
approx. 400,000
Onchocerciasis (river blindness)
Chagas disease (American trypanosomiasis)
Dengue/dengue hemorrhagic fever
Sleeping sickness (African trypanosomiasis)
Japanese encephalitis
Yellow fever4
Filariasis (lymphatic)
Rabies (dog-mediated)
1 Figures do not include lower respiratory infections related to measles, pertussis, and HIV infections.
2 Incidence figure refers to episodes.
3 Figure refers to chronic HBV carriers.
4 Officially reported figures only.
5 Figures relate to acute watery diarrhea, persistent diarrhea, and dysentery, but do not include measles- and HIV-related diarrhea.





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Newly Recognized Infectious Diseases
Source: World Health Organization
Year of recognition Agent Type Disease/comments
1973 Rotavirus virus major cause of infantile diarrhea worldwide
1975 Parvovirus B19 virus aplastic crisis in chronic hemolytic anemia
1976 Cryptosporidium parvum parasite acute and chronic diarrhea
1977 Ebola virus virus Ebola hemorrhagic fever
1977 Legionella pneumophila bacterium legionnaires' disease
1977 Hantaan virus virus hemorrhagic fever with renal syndrome (HRFS)
1977 Campylobacter jejuni bacterium enteric pathogen distributed globally
1980 human T-lymphotropic virus 1 (HTLV-1) virus T-cell lymphoma-leukemia
1981 toxin-producing strains of
Staphylococcus aureus
bacterium toxic shock syndrome
1982 Escherichia coli 0157:H7 bacterium hemorrhagic colitis; hemolytic uremic syndrome
1982 HTLV-2 virus hairy cell leukemia
1982 Borrelia burgdorferi bacterium Lyme disease
1983 human immunodeficiency virus (HIV) virus acquired immunodeficiency syndrome (AIDS)
1983 Helicobacter pylori bacterium peptic ulcer disease
1985 Enterocytozoon bieneusi parasite persistent diarrhea
1986 Cyclospora cayetanensis parasite persistent diarrhea
1986 BSE agent (uncertain) non-conventional agent bovine spongiform encephalopathy in cattle and possibly variant Creutzfeldt-Jakob disease (vCJD) in humans
1988 human herpes virus 6 (HHV-6) virus exanthem subitum
1988 hepatitis E virus virus enterically transmitted non-A, non-B hepatitis
1989 Ehrlichia chaffeensis bacterium human ehrlichiosis
1989 hepatitis C virus virus parenterally transmitted non-A, non-B liver hepatitis
1991 Guanarito virus virus Venezuelan hemorrhagic fever
1991 Encephalitozoon hellem parasite conjunctivitis, disseminated disease
1991 new species of Babesia parasite atypical babesiosis
1992 Vibrio cholerae 0139 bacterium new strain associated with epidemic cholera
1992 Bartonella henselae bacterium cat-scratch disease causing flu-like fever; bacillary angiomatosis
1993 Sin Nombre virus virus Hantavirus pulmonary syndrome
1993 Encephalitozoon cuniculi parasite disseminated disease
1994 Sabia virus virus Brazilian hemorrhagic fever
1995 human herpes virus 8 virus associated with Kaposi's sarcoma in AIDS patients
1995 Hepatitis G virus parenterally transmitted non-A, non-B hepatitis
1996 NvCJD TSE causing agent New variant Creutzfeldt-Jakob disease
1997 Avian influenza Type A(9H5N1) virus Influenza; can cause Reye syndrome


  The global count of people infected with HIV continues to increase at an alarming rate. Despite some notable successes with health education campaigns, millions are infected, with the worst infection rates being in the developing world.  
  Nevertheless, there are signs that the enormous scientific effort that has been mobilized against the disease is now paying dividends. Current drug regimes are able to prolong life and are even allowing scientists to debate the prospect of cure.  
  When HIV enters the body, the main cell type infected is the CD4+ T lymphocyte, a circulating white cell that plays an important role in controlling immune responses. In addition, the virus can enter a variety of other cell types that have the CD4 molecule on their surface. The net result of infection is a relentless fall in the number of CD4+ T cells and a gradual dismantling of the immune system's ability to fight off  




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Estimated Number of Deaths from HIV/AIDS in the World
Source: World Health Organization
Region Estimated deaths Region Estimated deaths
East Asia and Pacific 6,200 North America 29,000
Eastern Europe and Central Asia 300 Latin America 81,000
Australia and New Zealand 700 Caribbean 19,000
North Africa and Middle East 13,000 Sub-Saharan Africa 1.8 million
Western Europe 15,000 Total 2.3 million
South and Southeast Asia 250,000    


  infectious agents such as bacteria, fungi, and other viruses. This process leaves patients very susceptible to a wide variety of opportunistic infections and the appearance of rare tumors, many of which are virtually never seen in people with a normally functioning immune system. Pneumocystis carinü pneumonia, for instance, normally seen only in the malnourished or those whose immune systems have been deliberately suppressed, is common among AIDS patients and, for them, a leading cause of death. One important advance in the last few years has been the use of molecular assays to measure the amount of virus in the blood of infected patients. This procedure is valuable in predicting how rapidly they are likely to progress to an advanced state of the disease.  
  AIDS and HIV Information
  AIDS/HIV site offering safe sex and AIDS prevention advice, information about treatments and testing, and health/nutritional guidance for those who have contracted the disease.  
  early treatment The initial successes in the drug treatment of HIV infection were with agents that could treat or prevent the infectious complications of the disease. These drugs remain very valuable but do not have any activity against HIV itself. The first drug with proven activity against HIV was zidovudine (AZT). Zidovudine resembles one of the building blocks of DNA, and when HIV undergoes replication,  
HIV/AIDS: Regional Statistics and Features
Sub- Saharan Africa South and Southeast Asia Latin America Established Market Economies1 Caribbean Eastern Europe-Central Asia East
North Africa-Middle East2
Epidemic started
Late 1970s– early 1980s Late 1980s Late 1970s– early 1980s Late 1970s– early 1980s Late 1970s– early 1980s Early 1990s Late 1980s Late 1980s
Adults and children living with HIV/AIDS
20.8 million 6.0 million 1.3 million 1.4 million 310,000 150,000 440,000 210,000
Prevalence (%)
7.4 0.6 0.5 0.3 1.9 0.07 0.05 0.1
Women (%)
50 25 19 20 33 25 11 20
Main mode(s) of transmission for those living with HIV/AIDS2
Hetero Hetero-IDU MSM-IDU- Hetero MSM-IDU- Hetero Hetero IDU-MSM IDU-Hetero- MSM IDU-Hetero
1 North America, Western Europe, Australia, New Zealand, Japan.
2 Hetero: heterosexual transmission; IDU: transmission through injecting drug use; MSM: men who have sex with men.





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Current Total of Reported AIDS Cases in the World
Source: UNAIDS/WHO    
Category Group Number (millions)
New infections in 1997 adults 5.21
  children 0.59
  Total 5.80
People living with HIV/AIDS as of end 1997 adults 29.50
  children 1.10
  Total 30.60
HIV/AIDS associated deaths during 1997 adults 1.84
  children 0.46
  Total 2.30
Cumulative HIV/AIDS deaths adults 9.00
  children 2.70
  Total 11.70
Cumulative number of AIDS orphans1 children 8.20
1 Orphans are defined as HIV-negative children having lost their mother or both parents due to AIDS.


  zidovudine can bind to an essential HIV enzyme and prevent the virus from completing its life cycle. Zidovudine can improve the symptoms of HIV infection, is valuable in asymptomatic patients with low CD4+ T lymphocyte counts, and is effective at reducing the rate of transmission of HIV from pregnant women to their babies. However, when zidovudine is used alone, the virus is usually able to escape from the effects of zidovudine by mutating its DNA sequence. There is now an increasing appreciation of the need to use zidovudine in combination with some new antiviral drugs. This combination treatment of opportunistic infections extended the average length of survival with AIDS (in Western countries) from about 11 months in 1985 to 23 months in 1994.  
  new developments At the moment, probably the most exciting class of drugs that inhibit HIV replication is the protease inhibitors. When HIV replicates inside a cell it has to make a copy of its DNA, and then this genetic message is decoded into a protein. Some HIV proteins need to be broken down into smaller pieces in order to function, and this is done by a protease molecule. Normal function of the HIV protease appears to be vital for efficient replication of the virus, and over the last few years researchers have spent a great deal of effort in developing drugs that can block its function.  
  At least four protease inhibitors have been tried in clinical practice: saquinavir, ritonavir, nelfinavir, and indinavir. All have slightly different properties and different side effects. In clinical trials, these drugs have demonstrated a spectacular ability to reduce the amount of virus in the body. Sensitive molecular assays such as the polymerase chain reaction (PCR) have shown that the amount of HIV in blood can be reduced by over a thousandfold and sometimes may reach undetectable levels. Although effective on their own, most of the current drive in HIV therapeutics is to use these agents in combination with other anti-HIV agents. Typically this would include zidovudine, a protease inhibitor, and another agent such as didanosine.  
  In a recent trial this combination led to the virus being undetectable in 60% of patients after 24 weeks of treatment. A very encouraging observation with protease inhibitors is that they can be used at a very advanced state of the disease. It seems that the drugs should be used at quite large doses, to avoid the development of a resistant virus, and unfortunately they do have several side effects. Although most of these effects are not serious, many patients are unable to tolerate a particular drug combination; in these cases a change to another combination is indicated.  
  Antiviral Agents Bulletin
  News articles, abstracts, and patent details about antiviral treatments-including interferon and HIV-infection and AIDS-related therapeutics.  
  the role of combination therapy The exact role of combination therapy in the overall management of HIV infection is a subject of considerable debate at present. In an attempt to achieve consensus, a panel of the International AIDS Society-U.S.A. met in 1996. After results from many clinical trials, the group suggested that combination therapy was now the  




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  treatment of choice. It remains unclear, however, whether or not protease inhibitors should be used with all patients or just those at particular risk of rapid progression to full-blown AIDS based on measurement of the amount of HIV in their blood. Patients with symptoms should be offered treatment, but for those who are asymptomatic the situation is less clear and the decision will be based on the CD4+ count and the viral load in the blood. There are relatively little data to recommend how to treat patients who have been infected in the last month or two and are suffering from the typical symptoms of acute infection: fever, swollen lymph nodes, and headaches. As this is a time of intense viral replication, there is a theoretical advantage in using the strongest available treatment to limit the initial multiplication of the virus. This may also reduce the chance of the virus making mutations that would allow it to resist drug treatment.  
  The last few years have seen valuable advances in the treatment of HIV infection. Several powerful drugs are now available and are being tested in trials around the world. The human immunodeficiency virus has an astounding ability to mutate itself in order to evade drugs, and there are likely to be setbacks ahead. It is too soon to say whether or not some patients may be offered the prospect of complete cure. Nevertheless, many AIDS researchers are hoping that they can now maintain the upper hand in the battle against this formidable virus.  
  HIV Info Web
  Up-to-date information about HIV and AIDS treatments and other important resources for patients and their families, such as housing services and legal assistance.  
  costs The cumulative direct and indirect costs of HIV and AIDS in the 1980s have been conservatively estimated at $240 billion. The global cost—direct and indirect—of HIV and AIDS by the year 2000 could be as high as $500 billion a year—equivalent to more than 2% of global GDP.  
  tropical diseases  
  The concept of "tropical disease" first arose when Victorian Europeans explored the tropics and encountered diseases, in areas such as the "white man's grave" in West Africa, with which they were unfamiliar. However, it now usually encompasses all the diseases of the tropics, including those, such as tuberculosis, which are also common in temperate regions.  
  It is difficult for most of us to grasp the impact of tropical diseases on the human race because the numbers are so large. Of the 52 million deaths in 1996, for example, 40 million occurred in the developing world and 17 million of these (nearly three times the number killed by cancers worldwide) were caused by infectious or parasitic disease. Such disease accounts for 45% of all deaths in developing countries, compared with just over 1% in the rest of the world.  
  Disease in the tropics may be caused by poor nutrition, environmental factors and/or by living organisms such as fungi (ringworm, athlete's foot), viruses (polio, hepatitis A and B, yellow fever, some forms of meningitis), bacteria (travelers' diarrhea, typhoid, cholera, tetanus, tuberculosis, leprosy, legionnaires' disease, other forms of meningitis), the single-celled organisms known as protozoa (malaria, sleeping sickness, amoebic dysentery, Chagas's disease, leishmaniasis) and the worms known as nematodes (elephantiasis, river blindness, Guinea worm, hookworm, Strongyloides), trematodes (bilharzia) and cestodes (tapeworms, hydatid disease).  
  Yellow Fever
  Outbreak page on yellow fever. The Web site contains a section on frequently asked questions about the disease, and a section on current and recent outbreaks. The outbreaks section is updated regularly, often giving numbers of casualties and descriptions of operations by the World Health Organization to curb the spread of any outbreak.  
  Each of the living organisms has to get below the surface of the skin to survive. Some of the fungi live in the keratin just below the surface but the other pathogens need to get deeper, often into the bloodstream or gut. Several of them (the bacteria causing typhoid, cholera, other causes of diarrhea, the amoebas causing dysentery, the Ascaris roundworm, Guinea worm, hepatitis A virus and tapeworms) rely on us to swallow them in food or water or to ingest them accidentally as we touch our mouths with unclean hands. Other pathogens (some hepatitis B and human immunodeficiency viruses) rely on openings in the skin, caused by accident or injection, to gain access to the bloodstream, although HIV, hepatitis B and gonorrhea are mainly spread by sexual contact. As 30% of the populations of some towns in the tropics now carry HIV, sex (particularly unprotected sex) with a new partner is a life-threatening gamble.  
  The bacteria causing tuberculosis are drawn into our lungs from the air and those causing leprosy are mostly passed on in sneezes. A few parasites have stages in their life cycles which simply burrow into our skin, either from the soil (hookworm, Strongyloides) or water (bilharzia). Some of the most successful  




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  parasites of man (those causing malaria, sleeping sickness, river blindness, elephantiasis, yellow fever and leishmaniasis) spend part of their life cycle in insects (called the vectors of the pathogens) which distribute the parasites and later transmit them to humans as the insects feed.  
  The parasites causing malaria and elephantiasis use mosquitoes in this way, the nematodes of river blindness use blackflies (which breed in rivers, hence the name) and the trypanosomes of sleeping sickness and Chagas's disease use tsetse flies and bugs, respectively. Clean insects acquire the parasites when they feed on an infected individual. Most of the parasites do not simply use the vectors for distribution but also multiply and develop within them, the vectors acting as intermediate hosts of the parasites and humans as the definitive hosts.  
  malaria Malaria remains one of the most important parasitic diseases of humans. More than two-fifths of the world's population live in the 100 countries where transmission of malaria occurs and there are about 400 million clinical cases of malaria each year (1.5–2.7 million of them fatal). Human malaria may be caused by any of four species: Plasmodium falciparum, P. vivax and the rarer P. ovale and P. malariae. Although only one of these species (P. falciparum) causes fatal infections in humans, it is this species which is the most common and widespread, being present in 92 of the 100 countries where malaria transmission occurs. In fact, P. falciparum may cause more illness and deaths in humans than any other pathogen on earth.  
  Frequently Asked Questions About Malaria
  Outbreak page covering frequently asked questions on malaria. The Web site contains answers to a comprehensive list of questions regarding the disease, including thorough descriptions of the virus and its related diseases.  
  The malarial parasite injected by a feeding mosquito passes to the liver and multiplies there for a week or two. It then emerges, invades the red blood cells and multiplies again until the blood cells rupture and the released parasites invade more cells. It is the rupture of the infected red cells, which occurs more or less at the same time (every 2–3 days), that causes the first symptom of malaria: intermittent fever. After a while, some of the parasites breaking out of the blood cells develop into the sexual forms which are capable of infecting mosquitoes. Liver and kidney failure, severe anemia, convulsions, coma and/or death may develop in falciparum malaria. As malarial parasites in the liver are not affected by the majority of anti-malarial drugs in the bloodstream, any traveler who is infected in the last few days of their trip returns home with viable parasites. All travelers at risk of malaria must therefore continue to take anti-malarials for 4 weeks after leaving a malarious area, so that parasites emerging from the liver to infect the blood cells are killed. Two species causing human malaria (P. vivax and P. ovale) have special stages, called hypnozoites, which can lie dormant in the liver for months and sometimes years, and cause attacks of malaria when they eventually become active.  
  Life cycle of malaria parasite The life cycle of the malaria parasite is split between mosquito and
human hosts. The parasites are injected into the human bloodstream by an infected Anopheles
mosquito and carried to the liver. Here they attack red blood cells, and multiply asexually. The
infected blood cells burst, producing spores, or merozoites, which reinfect the bloodstream. After
several generations, the parasite develops into a sexual form. If the human host is bitten at this
stage, the sexual form of the parasite is sucked into the mosquito's stomach. Here fertilization
takes place, the zygotes formed reproduce asexually and migrate to the salivary glands ready
to be injected into another human host, completing the cycle.
  The relationship between an individual's natural resistance to disease (their level of immunity) and the severity of their suffering is an important one. Those who live in countries where tropical diseases are common are often exposed to the diseases many times and those that survive may have high levels of immunity to them. One individual infected with P. falciparum may stay healthy whereas another, infected in exactly  




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  Mosquito Though most of the more than 2,400 species of mosquito are tropical, they
are found worldwide. The banded-legged Culiseta annulata, lives in temperate zones.
Premaphotos Wildlife
  the same way but without any immunity to the infection, may die within 24 hours. This is why a traveler to such countries may suffer when all around appear healthy.  
  world travel The recent increase in the numbers of visitors to the tropics has meant that more of those from the developed world are putting themselves at risk of acquiring a tropical disease and of taking it home. Although there is usually little risk of the returned traveler passing on their disease, there is a major risk that it will not be diagnosed or treated correctly, simply because local physicians are unfamiliar with its signs and symptoms or fail to consider it. The symptoms and signs of malaria are so nonspecific that local physicians often take them to indicate influenza or gastritis unless the sick traveler mentions that they have visited a malarious area in the last year or more. Of those returning to the U.K. or U.S.A. and eventually dying of falciparum malaria, for example, almost 50% are misdiagnosed as cases of influenza or of another viral infection when first examined by their physicians. Fatal infectious or parasitic disease is fortunately rare in travelers to the tropics and accounts for only a small proportion of deaths in this group (most of the deaths are caused by accidents, especially road traffic accidents, or by cardiovascular disease in the older traveler).  
  The commonest afflictions the traveler to a developing country is likely to suffer are, in descending frequency, sunburn, diarrhea and vomiting (usually caused by Escherichia coli and of a few days' duration), malaria, acute infection of the respiratory tract (with fever) and hepatitis A. The chances of acquiring some of the perhaps better known diseases, such as leprosy, are virtually nil.  
  Anyone from a temperate country planning to visit a tropical country can take many steps to reduce their chances of developing a health problem as a result (prevention is always better than cure, particularly when the disease involved may be rapidly fatal and difficult to treat). It is important to be aware of the risks and how to avoid or minimize them. Travelers can educate themselves by contacting local travel health clinics, reading recent guides or exploring the World Wide Web; one of the best Web sites on travel health is run by the Centers for Disease Control and Prevention in Atlanta, Georgia ( Just in case a severe problem arises, travel insurance should be enough to cover the expenses of repatriation.  
  Travelers must take appropriate advice on what drugs and other measures they should take to protect themselves against malaria. As the malarial parasites continue to develop resistance to the drugs used against them, it is important to seek up-to-date information on the best drug or drugs to use in any particular area. Use of a bednet (preferably one impregnated with insecticide), keeping the skin covered and using an insect repellent (preferably one containing DEET) and insecticides (in mosquito coils or from electronic vaporizers) not only reduces the risk of being bitten by mosquitoes carrying malarial parasites but also limits the nuisance and loss of sleep caused by other biting insects.  




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Immunizations for Travelers
Source: Travel Health Online
Disease Immunization Timing Reaction Protection Duration of protection Other precautions Notes
cholera 2 injections not less than week apart 1 week to 1 month before departure soreness where injected, fever, headache, fatigue 50–60% 6 months avoid food or water that may be dirty low risk in reasonable tourist accommodation; infants under 6 months should not be vaccinated
hepatitis A (a) injection of immunoglobulin or (b) a vaccine consisting of 2 injections 1 month apart, then a 3rd injection 6–12 months later (a) just before travel (b) 2 months before (a) immunoglobulin –some may experience soreness and swelling at the injection site and, in some cases, hives (b) vaccine—soreness where injected, sometimes headache and fatigue (a) prevents illness (b) lessens its severity (a) 3 months (b) 10 years as typhoid  
hepatitis B 2 injections of vaccine 1 month apart, then booster 4 months later last injection 1 month before travel soreness where injected 80–95% perhaps 5 years   given to those at high risk, such as health workers, and is now also part of the recommended childhood vaccination series some antimalarial drugs are not recommended for pregnant mothers or children under 1 year
malaria none; take preventative tablets from 1 week before to 4 weeks after leaving malaria area order tablets 2 weeks before travel side effects are rare 90% only while tablets are taken use anti-mosquito sprays, mosquito nets; keep arms and legs covered after sunset  
polio (a) oral vaccine–3–4 doses (b) injection–3–4 shots, the best way to be protected is to get 4 doses of polio vaccine, immunized adults: 1 booster dose for travelers who are not up-to-date with their vaccination it may be necessary to allow as much as 7 months for the full recommended vaccination schedule, depending upon other vaccines that may be necessary for the trip

very rare cases develop polio 95+% 10 years   (a) should not be given to pregnant mothers (b) (injections) recommended only for people 18 years and older who have not yet been vaccinated, and for people who cannot take the oral vaccine because of health reasons; should not be given to a person who has had an allergy problem with the antibiotics neomycin or streptomycin the overall risk to travelers is low
rabies 3-dose series of injections, usually given on days 0, 7, and 21 or 28 5 weeks before travel swelling and itching where injected, headache, abdominal pain, muscle aches, nausea opinion divided as to whether vaccine prevents rabies or promotes a faster response to treatment 3 months avoid bites, scratches, or licks from any animal; wash any bite or scratch with antiseptic or soap as quickly as possible and get immediate medical  


  (table continued on next page)  




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  (table continued from previous page)  
Disease Immunization Timing Reaction Protection Duration of protection Other precautions Notes
tetanus normally given in childhood with booster every 10 years; unimmunized adults: 2 injections 1 month apart then 3rd injection 6 months later not critical headache, lethargy in rare cases >90% about 10 years wash any wounds with antiseptic recommended for those visiting areas in developing countries with poor food and water sanitation
typhoid 3 types of vaccine: (a) 1–2 injections 4–6 weeks apart (b) single injection (c) 4 oral doses, every-other-day series on days 1, 2, 4, and 6 5–7 weeks before departure soreness where injected, nausea, headache (worst in those over 35 and on repeat immunizations) may last 36 hours 50–70% (a) 1–3 years (b) 3 years (c)
1 year
avoid food, milk, or water that may be contaminated by sewage or by flies may only be available from special centers
yellow fever 1 injection at least 10 days before departure, but not more than 10 years before (arrival) possible slight headache and low fever 5–10 days later, muscle ache almost 100% 10 years against mosquitoes, as for malaria  
details correct at end August 1998


  International Travel and Health
  World Health Organization database of vaccination requirements for every country in the world. The site contains a mass of practical advice for international travelers. Information is regularly updated.  
  It is possible to be vaccinated against several tropical diseases (hepatitis A and B, yellow fever, polio, typhoid) before travel. Every traveler should be immunized against tetanus but the most common cholera vaccine is no longer generally recommended as it is not very effective (a new, more effective one is now on the market). As vaccination may take several weeks it is important to seek health advice early. Once in the tropics, personal hygiene is important and care should be taken with any food or drink. Any food should be cooked adequately and preferably eaten immediately after cooking (shellfish, ice cream and any raw foods, including salads and unpasteurized milk, are particularly hazardous). Any water to be drunk, if from a local source, is best boiled or sterilized chemically. Ice cubes (which may be made with contaminated water) are best avoided. Skin contact with fresh water should be avoided as much as possible as the water may contain the schistosome stages (cercariae) which can burrow into skin and lying directly on sand or walking barefoot should also be avoided. Most bouts of diarrhea only last a few days even if untreated, but plenty of safe fluids should be drunk (and the use of oral rehydration salts which can be bought and taken with the traveler should also be considered) to prevent dehydration.  
  antibiotic resistance  
  When, in 1969, the U.S. Surgeon-General announced that we could soon "close the book" on infectious diseases, he was speaking prematurely. For two years previously, first reports had surfaced of penicillin resistance developing in Pneumococcus, a bacterium which causes a number of potentially fatal diseases, including pneumonia and meningitis. Within little more than a decade, epidemics of pneumococcal disease were breaking out in many countries.  
  In 1995, when workers from the Centers for Disease Control and Prevention in Atlanta looked at samples taken from patients with severe pneumonia, they found that a quarter had been hit by pneumococcal (Staphylococcus pneumonia) strains resistant to penicillin; some 15% were also resistant to the antibiotic erythromycin. Today, growing resistance of this and other organisms to antibiotics is a global public health problem.  
  rise of the superbugs Bacteria vary greatly in their sensitivity to antibiotics, and there is no such thing as a "magic bullet" with blanket activity against all pathogens. The trouble is that, after more than half a century of antibiotic use, bacteria are mutating faster than new drugs can be found. The growth of super-resistance is being hastened by the indiscriminate use of antibiotics, including over-prescribing.  
  In the developed world, the danger is greatest in hospitals, where people are already very sick. Most at risk are people whose immune systems are in some way impaired, including the very young or the frail elderly, AIDS patients, organ transplant recipients, and patients receiving chemotherapy for cancer.  




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  Most notorious of the so-called ''superbugs" stalking hospital floors is methicillin-resistant Staphylococcus aureus (MRSA), a pathogen with an awesome talent for acquiring resistance traits from its microscopic neighbors. So far outbreaks of MRSA, which can cause temporary closure of operating rooms and intensive care units, have been met with vancomycin, a "last resort" antibiotic normally reserved for life-threatening infections. But in spring of 1997, the Japanese reported the most convincing evidence yet of the appearance of vancomycin-resistant strains.  
  Antibiotics: How Do Antibiotics Work?
  Introduction to the use and importance of antibiotics in easy to understand language. The site also includes a glossary of scientific and difficult terms, a further reading list, and an activities sheet.  
  The Japanese report brings one step closer the specter of the unstoppable "superbug" overrunning hospitals. In fact, microbiologists have been predicting just this scenario, not least because strains of the intestinal bacterium Enterococcus have for some time been defying all existing antibiotics, including vancomycin and the closely related teicoplanin. In the laboratory, it has been shown that genes for resistance can pass from Enterococcus to the more deadly S. aureus by plasmid transfer.  
  It was fear of an epidemic of untreatable infections that prompted the recent European ban on avoparcin, a drug administered to farm animals to promote growth. The rationale for antibiotic use in this context is that it improves feeding efficiency. However, avoparcin is close in chemical structure to vancomycin, and many scientists argue that its use as a growth promoter in livestock creates a potential reservoir of vamcomycin-resistant bacteria that would be transmissible to human beings.  
  return of old-time diseases The phenomenon of super-resistance means also that many one-time killer diseases, including tuberculosis (TB), typhoid, cholera, and diphtheria, are returning in force. TB, always a major problem in the Third World, is the biggest threat, since now it is making a comeback in countries where previously it had been brought under control. Moreover, some strains of the bacterium have become resistant. Parts of the country worst affected are deprived innercity areas where resistance is widespread.  
  A big factor in the spread of multi-drug resistant tuberculosis (MDRTB) has been failure of control programs in the industrialized countries. This has meant that many patients starting out on medication lapse before the six-month course is completed. If a patient carrying a resistant strain takes only one drug instead of the prescribed combination, or fails to complete the course, the effect is to promote resistant strains.  
  fresh strategies Bacteria developing the ability to foil an antibiotic can become permanently resistant, according to researchers at Emory University in Atlanta. They demonstrated this in another rising superbug, Escherichia coli, which causes gastrointestinal infections. This finding implies that, contrary to what many doctors previously believed, reducing antibiotic use will not eliminate resistant strains.  
  While the quest for new drugs to fight infection is now paramount, many researchers are developing fresh strategies. These include: tinkering with the structure of antibiotics to add in helper molecules; seeking to disable genes for resistance; and developing laser-activated chemical compounds to blitz the superbugs. Some teams, too, are reviving the old idea of turning bacteriophages (bacteria-eating viruses) loose on resistant bacteria.  
  All these strategies and more may be needed to overcome the rising toll exacted by antibiotic resistance. Certainly, with infectious diseases claiming more than 17 million lives a year worldwide, we are still no nearer to "closing the book."  
  mechanisms of resistance Bacteria may be naturally resistant to some antibiotics, or resistance may be acquired, mostly by the phenomenon of plasmid transfer. A plasmid is a free-floating fragment of DNA adrift in the cell cytoplasm. It carries some genetic material, including data governing the cell's resistance to antibiotics. Plasmids can be transmitted from one bacterium to another.  
  Occasionally resistance may be due to spontaneous mutation, which is the result of an error in replication of the cell's nuclear material during reproduction. Further reproduction causes the development of a resistant strain.  
  Bacteria demonstrate resistance in two ways. One way is by producing enzymes that disable drugs. A drug-defying enzyme is not always expressed by the organism targeted by therapy. The normally innocuous Staphylococcus epidermidis produces an enzyme that disables penicillin before it can act against harmful staphylococcal species; or some bacteria can contrive metabolic changes that foil the action of drugs. Sulfonamides—antibacterials introduced before the discovery of antibiotics—are often defeated by these metabolic readjustments on the part of bacteria.  




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  Noninfectious Diseases  
  This is a broad term that groups together all those disorders not caused by pathogens. It includes degenerative diseases, metabolic disorders, diet-related diseases, neurological and mental disorders, and birth defects. The following sections examine some of the most common noninfectious diseases prevalent today.  
  cardiovascular diseases  
  Cardiovascular diseases are those affecting the heart and blood vessels. This includes atherosclerosis, high blood pressure, heart attacks, and strokes.  
  Cardiovascular disease is one of the most common causes of death worldwide, but the distribution of the various types of cardiac diseases varies.  
  • In the United States more than a million deaths a year are due to ischemic heart disease.  
  • Hypertension is prevalent in the Caribbean and West Africa, and is the major cause of premature death from stroke.  
  • In countries where malnutrition occurs, heart failure develops, due to dietary deficiency diseases such as protein deficiency (kwashiorkor and marasmus) and beriberi (vitamin B1 deficiency).  
  • Rheumatic heart disease is common in countries with overcrowded and inadequate housing combined with poor hygiene, but is becoming much less common in the West.  
  atherosclerosis Atherosclerosis consists of accumulation of a variable combination of lipids, complex carbohydrates, blood and blood products, fibrous tissue, and calcium deposits in the lining of the arteries; this leads to thickening and hardening of the artery walls.  
  The main clinical forms of atherosclerotic disease arise from narrowing of the coronary arteries, the cerebral arteries, and the femoral artery and its branches.  
  hypertension Hypertension is abnormally high blood pressure due to a variety of causes, leading to excessive contraction of the smooth muscle cells of the walls of the arteries. It increases the risk of kidney disease, stroke, and heart attack.  
  American Heart Association
  Home page of the American Heart Association offers a risk assessment test, information about healthy living, including the effects of diet, and access to resources for both patients and caretakers.  
  Hypertension is one of the major public health problems of the developed world, affecting 15–20% of adults in industrialized countries (1996). It may be of unknown cause (essential hypertension), or it may occur in association with some other condition, such as kidney disease (secondary or symptomatic hypertension). It is controlled with a low-salt diet and drugs.  
  Preventing Recurrent Coronary Heart Disease
  Part of a collection of articles maintained by the British Medical Journal, this page features the full text of a May 9, 1998 editorial concerning coronary heart disease, in which the authors explain that lowering the heart rate may reduce mortality. In addition to the editorial, you will find a list of related articles from the BMJ's collection and the extensive PubMed collection. You can also search the collections under which this article appears, search other articles written by the authors of this article, and submit or read responses to this article.  
  coronary heart disease or ischaemic heart disease  
  This is a disorder caused by reduced perfusion of the coronary arteries due to atherosclerosis. It is the commonest cause of death in the Western world, leading to more than a million deaths each year in the United States and about 160,000 in the U.K.  
  Early symptoms of ischemic heart disease include angina or palpitations, but sometimes a heart attack is the first indication that a person is affected.  
  Risk of developing ischemic heart disease is particularly high in the U.K. Scotland has the highest mortality from cardiovascular disease of any country in the world, followed closely by England and Wales. In the United States, deaths from this cause declined steeply from 650 per 100,000 in 1968 to just over 300 in 1985, reflecting widespread public concern about the risks of atherosclerosis, but in England and Wales the rates have remained almost static.  
  heart attack or myocardial infarction This involves a sudden onset of gripping central chest pain, often accompanied by sweating and vomiting, caused by death of a portion of the heart muscle following obstruction of a coronary artery by thrombosis (formation of a blood clot). Half of all heart attacks result in death within the first two hours, but in the remainder survival has improved following the widespread use of thrombolytic (clot-buster) drugs.  
heart disease
  Deposits of calcium in diseased heart valves are sometimes actual bone tissue, possibly caused when heart cells follow a new developmental pathway as a result of inflammation.  


  After a heart attack, most people remain hospitalized  




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Death Rates for Cardiovascular Disease (CVD) in the World
Source: American Heart Association
(Figures indicate death rate per 100,000 population.)
CVD deaths
Total deaths
Czech Republic4
Northern Ireland2
Ireland, Republic of4
England and Wales2
New Zealand4
China (urban)2
Puerto Rico3
China (rural)2
Czech Republic4
China (urban)2
Northern Ireland2
China (rural)2
Ireland, Republic of4
England and Wales2
New Zealand4
Puerto Rico3
1 Data are for persons aged 35–74.
2 Data as of 1994.
3 Data as of 1992.
4 Data as of 1993


  for seven to ten days, and may make a gradual return to normal activity over the following months. How soon a patient is able to return to work depends on the physical and mental demands of his or her job. Despite widespread fears to the contrary, it is safe to return to normal sexual activity within about a month of the attack.  
  angina, or angina pectoris This is severe pain in the chest due to impaired blood supply to the heart  




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  muscle because a coronary artery is narrowed. Faintness and difficulty in breathing accompany the pain. Treatment is by drugs or bypass surgery.  
  stroke A stroke is an interruption of the blood supply to part of the brain due to a sudden bleed in the brain (cerebral hemorrhage) or embolism or thrombosis. Strokes vary in severity from producing almost no symptoms to proving rapidly fatal. In between are those (often recurring) that leave a wide range of impaired function, depending on the size and location of the event. Strokes involving the right side of the brain, for example, produce weakness of the left side of the body. Some affect speech. Around 80% of strokes are ischemic strokes, caused by a blood clot blocking an artery transporting blood to the brain. Transient ischemic attacks, or "mini-strokes," with effects lasting only briefly (less than 24 hours), require investigation to try to forestall the possibility of a subsequent full-blown stroke.  
  The disease of the arteries that predisposes to stroke is atherosclerosis. High blood pressure (hypertension) is also a precipitating factor—a worldwide study in 1995 estimated that high blood pressure before middle age gives a tenfold increase in the chance of having a stroke later in life.  
  Stroke Mini Fact Sheet
  Mini fact sheet and handy reference tool on strokes. It offers a brief description of the diagnostic symptoms, a list of the warning signs of the onset of the attack and suggested resources for further information on strokes, ways to prevent them, and also how to deal with them.  
  Strokes can sometimes be prevented by surgery (as in the case of some aneurysms), or by use of anticoagulant drugs or vitamin E or daily aspirin to minimize the risk of stroke due to blood clots. According to the results of a U.S. trial announced in December 1995, the clot-buster drug tPA, if administered within three hours of a stroke, can cut the number of stroke victims experiencing lasting disability by 50%.  
  In the U.S. around 500,000 people a year suffer a stroke, and it is the third commonest cause of death (after heart attack and cancer), and the main cause of disability.  
  heart failure This condition arises when the heart's pumping mechanism is inadequate. It results in back pressure of blood, causing congestion of the liver and lungs, failure of the peripheral blood supply and edema. It may be a consequence of hypertension or various types of heart disease. Treatment is with a diuretic and heart drugs, especially digoxin.  
  Drug Treatment in Heart Failure
  Part of a collection of articles maintained by the British Medical Journal, this page features the full text of a February 14, 1998 editorial concerning the treatment of heart failure, in which the author advocates the need for implementing "the new evidence on preventing coronary heart disease effectively in general practice."  
  rheumatic heart disease Rheumatic fever results from a Lancefield group A streptococcal infection causing tonsillitis and scarlet fever. The most important complication of rheumatic fever is damage to the heart and its valves, producing rheumatic heart disease many years later, which may lead to disability and death.  
  The various forms of cardiovascular disease are by no means always fatal. Many individuals survive, but with varying levels of disability. Cardiovascular diseases therefore account for a large proportion of the resources (both time and money) of a health service.  
  Cancer is a group of diseases characterized by abnormal proliferation of cells. Cancer (malignant) cells are usually degenerate, capable only of reproducing themselves (tumor formation). Malignant cells tend to spread from their site of origin by traveling through the bloodstream or lymphatic system. Cancer kills about 6 million people a year worldwide.  
  In some families there is a genetic tendency toward a particular type of cancer. In 1993 researchers isolated the first gene that predisposes individuals to cancer. About 1 in 200 people in the West carry the gene. If the gene mutates, those with the altered gene have a 70% chance of developing colon cancer, and female carriers have a 50% chance of developing cancer of the uterus. This accounts for an estimated 10% of all colon cancer.  
  In 1994 a gene that triggers breast cancer was identified. BRCA1 was found to be responsible for almost half the cases of inherited breast cancer, and most cases of ovarian cancer. In 1995 a link between BRCA1 and  
  Breast Cancer Awareness
  Promotes awareness of this disease through a library of frequently asked questions about breast cancer and mammograms, as well as a glossary of common terms and access to support groups. There is also information here about their fundraising activities and recipients of awards for people and groups seen to be contributing the most to the fight against this disease. It is sponsored by the make-up company Avon.  




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  non-inherited breast cancer was discovered. Women with the gene have an 85% chance of developing breast or ovarian cancer during their lifetime. A second breast cancer gene BRCA2 was identified later in 1995.  
  The commonest cancer in young men is testicular cancer, the incidence of which has been rising by 3% a year since 1974 (1998).  
  types of cancer There are over 100 different types of cancer. The following section details some of these.  
  Leukemia is one of a group of cancers of the blood cells, with widespread involvement of the bone marrow and other blood-forming tissue. The central feature of leukemia is runaway production of white blood cells that are immature or in some way abnormal. These rogue cells, which lack the defensive capacity of healthy white cells, overwhelm the normal ones, leaving the victim vulnerable to infection. Treatment is with radiotherapy and cytotoxic drugs to suppress replication of abnormal cells, or by bonemarrow transplant.  
  Abnormal functioning of the bone marrow also suppresses production of red blood cells and blood platelets, resulting in anemia and a failure of the blood to clot.  
  Leukemias are classified into acute or chronic, depending on their known rates of progression. They are also grouped according to the type of white cell involved.  
  lung cancer  
  The main risk factor for lung cancer is smoking, with almost nine out of ten cases attributed to it. Other risk factors include workspace exposure to carcinogenic substances such as asbestos, and radiation. Warning symptoms include a persistent and otherwise unexplained cough, breathing difficulties, and pain in the chest or shoulder. Treatment is with chemotherapy, radiotherapy, and surgery.  
  colon cancer  
  Incidence rates for carcinoma of the large intestine tend to be low in most African countries (0–5 per 100,000), higher in Asian countries (5–15), and much higher in North America, Europe and Australia (15–35). The disease is associated with affluence and coronary heart disease. There is also a positive correlation with the following dietary factors: high fat intake, high meat intake, and low fiber intake.  
  This is a highly malignant tumor of the melanin-forming cells (melanocytes) of the skin. It develops from an existing mole in up to two thirds of cases, but can also arise in the eye or mucous membranes.  
  Malignant melanoma is the most dangerous of the skin cancers; it is associated with brief but excessive exposure to sunlight. It is easily treated if caught early but deadly once it has spread. There is a genetic factor in some cases.  
  Once rare, this disease is increasing at the rate of 7% in most countries with a predominantly fair-skinned population, owing to the increasing popularity of holidays in the sun. Most at risk are those with fair hair and light skin, and those who have had a severe sunburn in childhood. Cases of melanoma are increasing by 4% a year worldwide. It strikes about 38,000 people a year in the United States.  
  Melanoma Skin Cancer Information
  Comprehensive information on melanoma from the American Cancer Society. Written in easily understandable language, this guide explains the normal function of the skin and nonmalignant cancers before turning to melanoma. There is information on risk factors, causes, diagnosis, treatment, latest research news, and prognosis for those with these highly malignant tumors.  
  factors that contribute to an individual's risk of developing cancer Current research shows that attention to diet and quitting smoking reduce an individual's risk of developing cancer.  
  Cigarette smoking is responsible for 90% of lung cancers among men and 79% among women—about 87% overall. Smoking accounts for about 30% of all cancer deaths. Those who smoke two or more packs of cigarettes a day have lung cancer mortality rates 12–25 times greater than those of nonsmokers.  
  nutrition and diet  
  Nutrition plays an important role in preventing cancer. Research indicates that people may reduce their cancer risk by observing these nutrition guidelines:  
  • Maintain a desirable weight. For people who are obese, weight reduction is a good way to lower cancer risk. Weight maintenance can be accomplished by reducing intake of calories and by maintaining a physically active lifestyle.  
  • Eat a varied diet. A varied diet eaten in moderation offers the best hope for lowering the risk of cancer.  
  • Include a variety of vegetables and fruits in the daily diet. Studies have shown that daily consumption of vegetables and fresh fruits is associated with a decreased risk of lung, prostate, bladder, esophagus, colorectal, and stomach cancers.  




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World Mortality from Cancer and Preventive Measures
Source: Worldwatch Institute
Cancers Deaths Dietary and lifestyle preventive measures
Trachea, bronchus, and lung 1,050,000 eliminate smoking
Stomach 765,000 increase fruit and vegetable consumption; reduce salt intake
Colon and rectum 525,000 reduce fat and protein consumption; increase vegetable consumption
Liver 505,000 reduce alcohol consumption; vaccinate against hepatitis B
Breast (female) 385,000 reduce fat and animal protein consumption; avoid obesity
Esophagus 355,000 eliminate smoking; reduce alcohol consumption
Mouth and pharynx 260,000 eliminate smoking; reduce alcohol consumption
Bladder 140,000 eliminate smoking; reduce alcohol consumption


  • Eat more high-fiber foods, such as whole grain cereals, breads, pasta, vegetables, and fruits. Highfiber diets are a healthy substitute for fatty foods and may reduce the risk of colon cancer.  
  • Cut down on total fat intake. A diet high in fat may be a factor in the development of certain cancers, particularly breast, colon, and prostate cancers. The American Cancer Society recommends reducing total fat intake to 30% or less of total calorie intake.  
  • Limit consumption of alcohol, if you drink at all. Heavy drinking, especially when accompanied by cigarette smoking or smokeless tobacco use, increases risk of cancers of the mouth, larynx, throat, esophagus, and liver.  
  • Limit consumption of salt-cured, smoked, and nitrite-cured foods. In areas of the world where salt-cured and smoked foods are eaten frequently, there is higher incidence of cancer of the esophagus and stomach. Modern methods of food processing and preserving appear to avoid the cancer-causing by-products associated with older methods of food treatment.  
  Almost all of the over 800,000 cases of basal and squamous cell skin cancer diagnosed each year in the United States are sun-related (ultraviolet radiation). Epidemiological evidence shows that sun exposure is a major factor in the development of melanoma and  
Recommendations for Early Detection of Cancer in People with No Symptoms
Source: American Cancer Society
Test Sex Age Frequency
Sigmoidoscopy, preferably flexible both >50 every 3–5 years
Fecal occult blood test both >50 every year
Digital rectal examination both >40 every year
Prostate examination1 male >50 every year
Breast self-examination female >20 every month
Breast clinical examination female 20–40 every 3 years
    >40 every year
Mammography2 female 40–49 every 1–2 years
    >50 every year
Pap test female all women who are, or who have been, sexually active, or have reached age 18, should have an annual Pap test and pelvic examination. After a woman has had 3 or more consecutive satisfactory normal annual examinations, the Pap test may be performed less frequently at the discretion of her physician
1 Annual digital rectal examination and prostate-specific antigen should be performed on men 50 years and older. If either result is abnormal, further evaluation should be considered.
2 Screening mammography should begin by age 40.





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  that incidence increases for those living near the equator.  
  smokeless tobacco  
  Use of chewing tobacco or snuff increases the risk of cancer of the mouth, larynx, throat, and esophagus, and is a highly addictive habit.  
  Estrogen treatment to control menopausal symptoms can increase risk of endometrial cancer. However, using progesterone with the estrogen helps to minimize this risk. Consultation with a physician will help each woman to assess personal risks and benefits. Continued research is needed in the area of estrogen use and breast cancer.  
  occupational hazards  
  Exposure to several different industrial agents, such as nickel, chromate, asbestos, vinyl chloride, increases risk of various cancers. Risk of lung cancer from asbestos is greatly increased when combined with cigarette smoking.  
  ionizing radiation  
  Excessive exposure to ionizing radiation can increase cancer risk. Most medical and dental X-rays are adjusted to deliver the lowest dose possible without sacrificing image quality. Excessive radon exposure (emitted by rocks in the earth's crust) in homes may increase risk of lung cancer, especially in cigarette smokers. If levels are found to be too high, remedial actions should be taken.  
  OncoLink-The University of Pennsylvania Cancer Center Resource
  As the title of this page says, a broad resource of cancer-related information for sufferers and their families. It includes sections on "causes, screening, and prevention," "clinical trials," and "conferences and meetings."  
  treatment Cancer is one of the leading causes of death in the industrialized world, yet it is by no means incurable, particularly in the case of certain tumors, including Hodgkin's disease, acute leukemia, and testicular cancer. Cures are sometimes achieved with specialized treatments, such as surgery, chemotherapy with cytotoxic drugs, and irradiation, or a combination of all three. Monoclonal antibodies have been used therapeutically against some cancers, with limited success. There is also hope of combining a monoclonal antibody with a drug that will kill the cancer cell to produce a highly specific magic bullet drug. In 1990 it was discovered that the presence in some patients of a particular protein, p-glycoprotein, actively protects the cancer cells from drugs intended to destroy them. If this action can be blocked, the cancer should become far easier to treat.  
  Cancer: The Facts
  Information on cancer from the Imperial Cancer Research Fund. There is a simple explanation of what cancer is, followed by links to different types of cancer-bowel, leukemia, lung, pancreatic, skin, and multiple myeloma cancers, as well as cancers specific to either men or women, or prevalent within families. Cancer statistics are also given.  
  Diabetes mellitus is a disorder of the islets of Langerhans in the pancreas which prevents the body from producing the hormone insulin, so that sugars cannot be used properly. Treatment is by strict dietary control and oral or injected insulin, depending on the type of diabetes.  
  There are two forms of diabetes: Type 1, or insulin-dependent diabetes, which usually begins in childhood (early onset) and is an autoimmune condition; and Type 2, or noninsulin-dependent diabetes, which occurs in later life (late onset).  
  In diabetes, sugar accumulates first in the blood and then in the urine. The patient experiences thirst, weight loss, and copious voiding, along with degenerative changes in the capillary system. Without treatment, the patient may go blind, ulcerate, lapse into diabetic coma, and die. Early-onset diabetes tends to be more severe than that developing in later years, and its  
Symptoms of Diabetes
Source: American Diabetes Association
Type of diabetes Symptoms
Type I (IDDM)1 frequent urination
excessive thirst
extreme hunger
dramatic weight loss
weakness and fatigue
nausea and vomiting
high levels of sugar in the blood
high levels of sugar in the urine
Type II (NIDDM) any of the IDDM symptoms
recurring, hard-to-heal skin or
bladder infections
blurred vision
tingling or numbness in extremities
1 Symptoms usually occur suddenly.





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  incidence has almost doubled since the 1970s; it now affects 1 in 500 people. Before the discovery of insulin by Frederick Banting and Charles Best, severe diabetics did not survive.  
  Careful management of diabetes, including control of high blood pressure, can delay some of the serious complications associated with the condition, which include blindness, disease of the peripheral blood vessels and kidney failure. A continuous infusion of insulin can be provided via a catheter implanted under the skin, which is linked to an electric pump. This more accurately mimics the body's natural secretion of insulin than injections or oral doses, and can provide better control of diabetes. It can, however, be very dangerous if the pump malfunctions.  
  In 1997, there were about 135 million sufferers worldwide.  
  risk factors In the majority of patients diabetes is a primary disorder, but it may arise secondary to other diseases that impair the function of the pancreas. An individual's risk of developing diabetes is affected by:  
  • genetic factors  
  • dietary factors such as obesity, dietary restriction, sugar intake and fiber intake  
  • infections  
  • stress  
  • other diseases that destroy the pancreas or impair insulin secretion  
  To remember the role of insulin:  
  Remember that insulin gets into cells. Without insulin, a person can have excess sugar in the blood yet die of lack of sugar.  


  treatment for diabetes Treatment emphasizes control of blood glucose through blood glucose monitoring, regular physical activity, meal planning, and attention to relevant medical and psychosocial factors. In many patients, oral medications and/or insulin injections are also required for appropriate blood sugar (glucose) control. Treatment of diabetes is an ongoing process that is planned and regularly reassessed by the health-care team, the person with diabetes, and his or her family. Patient and family education are important parts of the process.  
  Type I diabetes  
  The goal of the Type I diabetes treatment plan is to keep the blood-sugar level as close to normal as possible (good blood-sugar control). A treatment plan will probably include:  
  Insulin to lower blood sugar. A health-care practitioner will prescribe for each patient the dosage, frequency, and type of insulin. Insulin must be injected into the fat below the skin to be effective. It cannot be taken as a pill because the stomach juices would destroy the insulin before it could work. Scientists are looking for new ways to give insulin.  
  Specified foods to increase blood sugar. Most people with Type I diabetes have a personal meal plan made up by a registered dietician, detailing the amount of food and when it should be eaten. Most diets include three meals and at least two snacks a day.  
  Exercise to help the body use and lower blood sugar. Generally, a health-care practitioner prescribes exercise as part of the daily routine.  
  Blood and urine testing to determine blood-sugar levels. These tests are simple. The blood test requires only a drop of blood from a finger-prick, which patients can learn to do at home, as well as how to use the results. Urine tests, which may be needed to test for substances in the body called ketones, can also be done by the diabetic at home. Ketones in the urine may indicate that the diabetes is not being adequately controlled.  
  Type II diabetes  
  The goal of the Type II diabetes treatment plan is to keep the blood-sugar level as close to normal as possible (good blood-sugar control). A treatment plan will probably include:  
  Healthy diet and regular exercise Type II diabetes can often be controlled through diet and exercise alone. But some people also need medicine—either diabetes pills or insulin shots. Many people find their diabetes gets better when they follow their treatment plan.  
  Losing weight to help some overweight people to bring their blood sugars into the normal range. People who have a tendency to get Type II diabetes can try to avoid the condition by losing weight or not becoming overweight. (The health-care practitioner may allow some overweight people to stop their medication so long as they lose weight and follow a good meal plan.)  
  Recent Advances: Diabetes
  Part of a collection of articles maintained by the British Medical Journal, this page features the full full text of an April 18, 1998 clinical review regarding the alarming rise in the number of patients with diabetes around the world. The text includes diagrams, and there is a list of references.  




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  Blood and urine testing: the health-care practitioner may also want the patient to test blood-sugar levels regularly, to check that the diabetes is under control.  
  complications with diabetes  
  short-term complications  
  Hypoglycemia, or low blood sugar, sometimes called an insulin reaction, occurs when the blood sugar drops too low. This problem can be corrected by eating some sugar, for example glucose tablets or chocolate.  
  Hyperglycemia, or high blood sugar, occurs when the blood sugar is too high. It can be a sign that diabetes is not well controlled.  
  Ketoacidosis, or ketone poisoning, occurs when the metabolism of fat is not being controlled by the treatment. It is very serious and may lead to coma.  
  long-term complications  
  Heart disease (cardiovascular disease) is more common among people with diabetes.  
  Stroke the risk of stroke is higher among people with diabetes.  
  High blood pressure is more common among diabetics.  
  Blindness diabetes is the leading cause of new cases of blindness among adults. Diabetes affects the retina in the eye and causes many new cases of blindness each year.  
  Kidney disease (treatment by dialysis or transplant) diabetes is the leading cause of end-stage renal disease.  
  The efficient management of patients with diabetes presents an opportunity for good medical and dietetic practice, and unlike other chronic diseases a great difference can be made to the patient's life. The etiology of diabetes and restriction of its long-term complications continues to be a challenge to medical research today.  
  diet and diseases  
  Nutrition has had an important role in promoting health and in preventing and treating diseases for thousands of years. It is well documented that Hippocrates frequently gave advice to his patients on the types of food they should be eating. However, the concerns of modern day reflect not only the importance of receiving sufficient amounts of food and nutrients, but also problems that have arisen through the lifestyle factors of affluent societies. Such diseases as obesity, cancer, and cardiovascular diseases can be directly linked to diet.  
  Dietary requirements may vary over the life span of an animal, according to whether it is growing, reproducing, highly active, or approaching death. An adequate diet for humans is one that supplies the body's daily nutritional needs and provides sufficient energy to meet individual levels of activity. The average daily requirement for men is 2,500 calories, but this will vary with age, occupation, and weight; in general, women need fewer calories than men. The energy requirements of active children increase steadily with age, reaching a peak in the late teens. At present, about 450 million people in the world—mainly living in famine or poverty stricken areas, especially in Third World countries—subsist on fewer than 1,500 calories per day. The average daily intake in developed countries is 3,300 calories.  
  A well-balanced diet is essential to ensure the body's peak performance. There are many factors that determine an individual's energy requirements—such as age, sex, occupation, and general lifestyle—and so it is important that diets provide the right amount of energy to match individual needs. In addition to energy-producing carbohydrates, however, the body has many other nutritional requirements, and so the emphasis of a healthy, well-balanced diet is not just a matter of calorie-counting, but ensuring that all the components (nutrients) that together comprise a well-balanced diet are present in adequate and correct amounts.  
  Essential nutrients are those substances that are necessary for growth, normal functioning, and maintenance of life; they must be supplied by food because they cannot be made by the body. The main nutrients known to be essential for humans are:  
  • amino acids (proteins)  
  • carbohydrates  
  • essential fatty acids (fats)  
  • vitamins  
  • minerals and trace elements  
  • water  
  proteins These are made up of smaller units called amino acids. There are about twenty different kinds of amino acids. The primary function of dietary protein is to provide the amino acids required for growth and maintenance of body tissues and to regulate metabolism. Proteins are also needed by the white cells in the blood to produce antibodies; these assist the body's immune system to ward off attacks by bacteria and viruses. All fruits and vegetables contain some protein; good sources include peas, beans, lentils, grains, nuts, seeds, and potatoes. Animal proteins include milk, cheese, meat, eggs, and fish.  
  carbohydrates Carbohydrates are composed of carbon, hydrogen, and oxygen. The major groups are starches,  




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  sugars, and cellulose and related material (or "roughage"). The prime function of the carbohydrates is to provide energy for the body; they also serve as efficient sources of glucose, which the body requires for brain functioning, utilization of foods, and maintenance of body temperature. Roughage includes the stiff structural materials of vegetables, fruits, and cereal products.  
  fats Fats are composed of glycerol and fatty acids and, like carbohydrates, contain carbon, hydrogen, and oxygen atoms. There are two types of fatty acids: saturated and unsaturated. Unsaturated fatty acids are found in fish oils and vegetable oils—coconut oil and palm oil are the only saturated vegetable oils. Most saturated fats are animal fats, and are solid, such as lard and butter. Margarine is saturated by the process of hydrogenation which forces hydrogen gas through vegetable oil. Fats provide the most concentrated form of energy: in other words, when they are burned in the body, they supply more than twice the number of calories per gram available from carbohydrates. They are also high in cholesterol. Hence the need to control fat intake where obesity and cholesterol levels present a health problem. Heart disease has been linked to the consumption of hydrogenated fats. However, fats are a necessary part of any well-balanced diet. They provide insulation, build cells, and facilitate metabolism. Unsaturated fatty acids are essential for healthy skin, circulation, bone, brain, and nerves.  
  Most fatty acids can be synthesized by the body, with the exception of three, the essential fatty acids (EFAs): linoleic acid, linolenic acid, and arachidonic acid. These have to be supplied from food; vegetable oils, particularly if they are unrefined and cold pressed, are the best sources of EFAs. Sunflower and safflower oils are among the richest sources, containing up to 90%. EFAs are vital for the maintenance of good health. Among their many uses, they help to prevent atheroschlerosis (coronary heart disease) and the formation of blood clots in arteries, and they regulate such diverse reactions as stomach secretions, hormone release, and pancreatic function.  
  Your Body and Nutrition
  Information and pictures on the way the human body works. There are pages on different cell functions and the importance of free radicals. Each page is accompanied by a picture and a brief explanation. It is a commercially sponsored site, but there is a lot of good and free biological information here.  
  vitamins These are organic substances which are used by the body in very small amounts but are vital for normal body chemistry. They are all obtained from food, but vitamin D is also produced by the action of daylight on the skin, and vitamin K is produced by microorganisms in the bowel. An insufficient intake of one or more vitamins can result in a wide range of deficiency diseases. For instance, vitamin A, which can be found in eggs, milk, dairy products, fish liver oil, and animal liver, helps to maintain the cells lining the respiratory system and the mucous membranes of the eyes, ear, nose throat, and bladder; it helps to fight colds and a deficiency of the vitamin can lead to respiratory infections.  
  Some sixteen different B vitamins have been isolated, and as they usually occur together, they are known as vitamin B complex. They can be found in vegetables and animal foods, such as organ meats (particularly liver), wholewheat bread, yeast extract, and brown rice, and are vital for converting carbohydrates to glucose and food into energy. When B vitamins are lacking in the body, carbohydrates are not fully utilized and this can result in stress, nervousness, constipation, fatigue, and indigestion. Most of the complex are concerned with various processes in the liver, eyes, skin, and hair, and have a wide range of effects from alleviating stress to preventing atherosclerosis.  
  Vitamin C (ascorbic acid) is a very unstable, water-soluble vitamin, which is easily lost in food preparation—not only in cooking, but also in peeling, stoning, and soaking fruits and vegetables. Among its best natural sources are citrus fruits, peppers, broccoli, tomatoes, cabbage, green leafy vegetables, and potatoes. Vitamin C has many functions in the body, among the best known of which are the prevention of scurvy, a skin condition, and fighting the symptoms of the common cold. In addition, it helps to form collagen (a subskin "cement"), increases immune responses to infectious diseases, and has been found to lower the risk of cancers of the mouth, esophagus, lung, stomach, colon, cervix, and breast. It has also been shown by several studies to lower cholesterol levels. Human beings are one of very few mammals that cannot synthesize vitamin C, and a regular daily intake from a food source is necessary.  
  Vitamin D is a fat-soluble vitamin which is supplied from both food, especially milk and dairy foods, and exposure to the sun. It is stored mainly in the liver, but also in smaller quantities in the skin, brain, and bones. Vitamin D promotes absorption of calcium and phosphorus which are both vital for strong teeth and bones, and for the prevention of rickets in children. It also helps to maintain a healthy nervous system, normal heartbeat, and efficient blood clotting. Since vitamin D is scarce in vegetables, people who do not drink milk may need to supplement their diet with cod liver oil and fish such as sardines, herring, salmon, and  




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Vitamin Name Main dietary sources Established benefit Deficiency symptoms
A retinol dairy products, egg yolk, liver; also formed in body from b-carotene, a pigment present in some leafy vegetables aids growth; prevents night blindness and xerophthalmia (a common cause of blindness among children in developing countries); helps keep the skin and mucous membranes resistant to infection night blindness; rough skin; impaired bone growth
B1 thiamin germ and bran of seeds and grains, yeast essential for carbohydrate metabolism and health of nervous system beriberi; Korsakov's syndrome
B2 riboflavin eggs, liver, milk, poultry, broccoli, mushrooms involved in energy metabolism; protects skin, mouth, eyes, eyelids, mucous membranes inflammation of tongue and lips; sores in corners of the mouth
B6 pyridoxine/ pantothenic acid/biotin meat, poultry, fish, fruits, nuts, whole grains, leafy vegetables, yeast extract important in the regulation of the central nervous system and in protein metabolism; helps prevent anemia, skin lesions, nerve damage dermatitis; neurological problems; kidney stones
B12 cyanocobalamin liver, meat, fish, eggs, dairy products, soybeans involved in synthesis of nucleic acids, maintenance of myelin sheath around nerve fibers; efficient use of folic acid anemia; neurological disturbance
  folic acid green leafy vegetables, liver, peanuts; cooking and processing can cause serious losses in food involved in synthesis of nucleic acids; helps protect against cervical dysplasia (precancerous changes in the cells of the uterine cervix) megaloblastic anemia
  nicotinic acid (or niacin) meat, yeast extract, some cereals; also formed in the body from the amino acid tryptophan maintains the health of the skin, tongue, and digestive system pellagra
C ascorbic acid citrus fruits, green vegetables, tomatoes, potatoes; losses occur during storage and cooking prevents scurvy, loss of teeth; fights hemorrhage; important in synthesis of collagen (constituent of connective tissue); aids in resistance to some types of virus and bacterial infections scurvy
D calciferol, cholecalciferol liver, fish oil, dairy products, eggs; also produced when skin is exposed to sunlight promotes growth and mineralization of bone rickets in children; osteomalacia in adults
E tocopherol vegetable oils, eggs, butter, some cereals, nuts prevents damage to cell membranes anemia
K phytomenadione, menaquinone green vegetables, cereals, fruits, meat, dairy products essential for blood clotting hemorrhagic problems


  tuna. Overdoses of the vitamin can lead to toxicity symptoms such as diarrhea, nausea, excessive urination, and kidney damage.  
  minerals and trace elements These are inorganic substances vital to normal development; calcium and iron are particularly important as they are required in relatively large amounts. Minerals required by the body in trace amounts include chromium, copper, fluoride, iodine, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium, and zinc. The relative proportions of these nutrients in the diet can influence health. If a particular nutrient is present in insufficient quantities then deficiency symptoms can result. Likewise, if too much of a certain nutrient is present in the diet then toxic symptoms may occur or this may lead to other disease-associated manifestations. For instance, calcium, which is found in milk, cheese, and bread, is necessary for healthy bones and teeth. A deficiency of this mineral can result in brittle bones and teeth. Similarly, phosphorus, which is contained in milk, is also needed in the formation of bones and teeth. Iron, which is present in liver and egg yolk, is used by the body in the manufacture of hemo-  




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Nutritive Value of Foods
Source: UK Ministry of Agriculture, Fisheries and Food
The energy value of each food is given in kilojoules (kJ) and kilocalories (kcal), and both have been calculated from the protein, fat, and carbohydrate content per 100 g of edible portion.
Protein (g) Fat (g)
fat (g)
Cereal and Cereal Products            
Bread, brown
Bread, white
Flour, plain, white
Flour, wholewheat
Oats, oatmeal, raw
Rice, brown, boiled
Rice, white, boiled
Spaghetti, white, boiled
Dairy Products            
Cheddar cheese
Cottage cheese
Cream, fresh, heavy
Cream, fresh
Eggs, boiled
Low-fat spread
Margarine, polyunsaturated
Milk, semiskim
Milk, skim
Milk, whole
Yogurt, whole milk, plain
White fish, steamed, flesh only
Shrimps, boiled
Beef, lean only, raw
Chicken, meat and skin, raw
Lamb, lean only, raw
Pork, lean only, raw


  (table continued on next page)  




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  (table continued from previous page)  
Protein (g) Fat (g)
fat (g)
Potatoes, new, flesh only
Potatoes, old, flesh only
Sweetcorn kernels
Sweet potatoes
Tofu, soybean, steamed


  globin; a deficiency of this mineral can result in various forms of anemia.  
  water Water is involved in nearly every body process. Animals and humans will succumb to water deprivation sooner than to starvation.  
  the Western diet  
  During the twentieth century with the advent of food processing techniques, people have been able to ''refine," "process," and "add" to food. While this has increased the quantity and range of food that an  
Dietary Components of Traditional, Mediterranean, and Western Diets
Source: Worldwatch Institute
(N/A = not available.)
Dietary components Diet     WHO recommendations
  Traditional Mediterranean Western  
Complex (starch) (% of dietary energy) 60–75 N/A 28 45–55
Simple (sugar) (% of dietary energy) 5 N/A 22 10
Total (% of dietary energy) 65–80 >50 50 55–65
Fats and Oils        
Saturated fats (% of dietary energy) approx. 10–15 <8 18–30 10–15
Total (% of dietary energy) <20 30–37 38–43 20–30
Protein (% of dietary energy) 10 8–12 12 8–12
Cholesterol (mg per day) <100 approx. 300–500 approx. 500 <300
Salt (g per day) 5–15 N/A 15 5
Fiber (g per day) 60–120 7–11 7 >30





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Recommended Weight Tables
Source: Metropolitan Life Insurance Company
Height Small frame weight Medium frame weight Large frame weight
m ft/in kg
Men Aged 25 and Over
1.55 5'1" 48–51
1.57 5'2" 49–53
1.60 5'3" 50–54
1.63 5'4" 52–55
1.65 5'5" 53–57
1.68 5'6" 55–59
1.70 5'7" 57–61
1.73 5'8" 59–68
1.75 5'9" 60–65
1.78 5'10" 62–67
1.80 5'11" 64–69
1.83 6'0" 66–70
1.85 6'1" 68–73
1.88 6'2" 69–74
1.91 6'3" 71–76
Women Aged 25 and Over
1.45 4'9" 41–44
1.47 4'10" 42–45
1.50 4'11" 43–47
1.52 5'0" 45–48
1.55 5'1" 46–49
1.57 5'2" 47–51
1.60 5'3" 49–52
1.63 5'4" 50–54
1.65 5'5" 52–56
1.68 5'6" 54–58
1.70 5'7" 55–59
1.73 5'8" 57–62
1.75 5'9" 59–64
1.78 5'10" 61–65


  individual can sample, in some cases it has also had a deleterious effect on the nutritional quality of food, with direct consequences for health and well-being.  
  The so-called "Western diet" of affluent societies leaves much to be desired. Unlike traditional diets and diets of those people living in Mediterranean countries it either lacks certain beneficial nutrients or contains too much of others. Compared to a traditional diet, a Western diet contains:  
  • too much refined carbohydrates and sugar;  
  • too much saturated fats, mostly animal fats;  
  • too much cholesterol;  
  • too much salt;  
  • insufficient fiber;  
  • too many processed foods;  
  • too much tea, coffee, and alcoholic beverages;  
  • pesticide residues and other potentially harmful food additives;  
  A Western diet can lead to diseases such as obesity.  
  obesity Obesity is the most prevalent nutritional disorder in prosperous communities and is the result of an energy imbalance. An individual is considered to be obese when they have a Body Mass Index (BMI) in excess of 30. The BMI is calculated by taking the individual's weight in kilograms and dividing this by the height in meters. Obesity occurs when energy intake exceeds actual energy expended, so the unused energy is stored as body fat. A BMI of over 30 is a hazard to health, and is now common enough in the Western  




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  world to constitute one of the most important medical and public health problems, putting the individual at high risk of degenerative diseases or even death, and these risks increase as the BMI increases.  
  Obesity has been attributed to numerous causes including excessive intake, reactive eating due to stress or anxiety, low resting metabolic rate influencing the caloric value of energy expenditure, environmental effects, family behavior problems, and genetic factors. Other influences include human biology, endocrine alterations, society, culture, and physical activity. It is a complex issue.  
  genetic influence  
  An individual's genetic composition (their genotype) has a specific influence on their sex, height, eye color, and skeleton, and may also influence their body and muscular mass, as well as body fat and how this is regionally distributed. The variation in body fat distribution may also result from a complex interaction of physical, environmental, and social features, as well as from the genotype. Each gene may have a varying or specific influence with many genes each exerting a small effect, or perhaps a single rarer gene that plays a larger role over time, with inherited differences in the likelihood of developing obesity.  
  Each genotype may have its own particular influence, with a single gene defect influencing obesity, or it may exert several independent (polygenic) influences, including regulation of energy expenditure (or metabolism). For example, there may be a form of thrifty genotype that has developed over time, and which influences the more efficient use of energy intake. The body fat itself may consist mainly of enlarged fat cells, or there may be a larger number of smaller fat cells, each of which may have a specific genotype influence. Perhaps there is no particular gene that influences the development and/or maintenance of obesity, but probably several genes and aspects of human physiology that determine many aspects of weight, appetite, satiety, metabolism, and a predisposition to physical activity. Families may have shared genes, and they often share the same environment and particular eating patterns—also influential factors that need to be examined separately. With regard to body fat variation, the additive genetic effect on the amount of subcutaneous fat is considered to be quite low, but has been reported as highest for fat mass and regional distribution of the fat, which suggests that the genotype may be more influential on the visceral (deep) fat than the subcutaneous store. From the limited data available it appears that the genotype could account for up to 40% of the individual differences in the resting metabolic rate, the thermic effect of food, and the energy cost of light exercise, which would explain why some people become obese.  
  Studies of obesity in families show there is possibly a familial influence; for example, in a series of studies of the families of obese children, it was found that a child with one obese parent was at greater risk of developing obesity, but surprisingly also that those with two obese parents were at a lesser risk. This shows how complex this issue is and demonstrates the need for much more investigation.  
  Studies of adopted children and both their biological and adoptive parents suggest that inheritance plays an important role in the risk of developing obesity. Research has shown that there was no relationship between the BMI of the child and the adoptive parents, but that the BMI of the biological parents actually increased with that of the child whose weight was increasing.  
  Further evidence for the effect of the genotype and its influence has come from work examining the body weight of twins, where nearly two-thirds of the variability in BMI was attributed to genetic factors. The body weight of twins of the same sex (monozygotic) has been found to have identical genetic features and is more similar than the body weight of twins of different sexes (dizygotic). The genetic features of dizygotic twins are similar to those of other siblings.  
  Obesity appears to be more prevalent in the families of obese patients seeking surgical treatment for their condition than in a group of nonobese patients treated with other abdominal surgery. In approximately 10% of the families of the patients seeking help, more than one other member sought treatment. The incidence of obesity in the families of these patients was compared with that in a group of nonobese patients, and it was found that there were significantly more obese family members in the obese group. These included mothers and daughters, fathers and daughters, sisters and brothers, all with a BMI of over 35. This would suggest a genetic influence, and a need for further investigations into these factors.  
  There are also certain inherited syndromes where obesity is one of the characteristics. These include, in particular, Prader-Willi Syndrome, where children develop a ravenous appetite and a variety of foodseeking behaviors, with parents fighting a losing battle to control the child's intake. The Bardet—Biedl Syndrome is transmitted via an autosomal recessive trait, with obesity occurring in up to 80% of the cases.  
  There appears to be some single and polygenic influence on the transmission of obesity, although the genetic influence is more important in determining body fat distribution, and studies show that it may run in families, but one needs to examine separately the influences of the environment and the genes.  




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  anorexia In the wealthier developed countries of the world, many instances of primary deficiency diseases are self-inflicted and the direct result of weight-loss and slimming regimes, whereby essential nutrients are omitted from the basic diet.  
  Anorexia is a lack of desire to eat, or refusal to eat, and can result in the pathological condition of anorexia nervosa, most often found in adolescent girls and young women. Anorexia nervosa is characterized by severe self-imposed restriction of food intake. The consequent weight loss may lead, in women, to absence of menstruation. Anorexic patients sometimes commit suicide. Anorexia nervosa is often associated with increased physical activity and symptoms of mental disorders. Psychotherapy is an important part of the treatment.  
  The mental Health Foundation estimated in 1997 that as many as 1 in 20 people (of which the vast majority are women) display symptoms of anorexia, although most of them are never formally diagnosed. About 1 sufferer in 100 needs long-term treatment, and of these one-fifth die, half from starvation and half from suicide.  
  The causes of anorexia nervosa are not known. Teenage pressures and family rivalries and hostilities may be contributive factors. The anorectic may be trying to attain an "ideal" figure, or may be resisting becoming a grown-up woman like her mother. She often thinks of herself as without an identity of her own. The condition also occurs with older women and, very rarely, with men.  
  deficiency diseases Deficiency diseases are widespread in developing countries. In many areas the combined effects of drought and civil war mean that harvests do not provide sufficient food to feed the people and many die from starvation.  
  The World Health Organization estimated in 1995 that one-third of the world's children are undernourished. According to UNICEF, in 1996 around 86 million children under the age of five (50% of all under-fives) in South Asia were malnourished, compared to 32 million (25%) in sub-Saharan Africa.  
  In a report released at the World Food Summit in Rome in 1996, the World Bank warned of an impending international food crisis. In 1996, more than 800 million people were unable to get enough food to meet their basic needs. Eighty-two countries, half of them in Africa, did not grow enough food for their own people; nor could they afford to import it. The World Bank calculated that food production would have to double over the next 30 years as the world population increases. Contrary to earlier predictions, food stocks and particularly grain stocks have fallen during the 1990s.  
  Nutritional deficiency diseases can be divided into two categories: primary deficiency diseases which are a direct result of an inadequate supply of an essential nutrient; and secondary deficiency diseases which result from the body's failure to make adequate use of an essential nutrient. This can be due either to an inability to absorb the nutrient, or an inability to metabolize the nutrient once it has been absorbed.  
  In the poorer countries of the Third World and developing nations primary deficiency diseases are, for the most part, endemic to regions where poverty and famine are common, or where essential nutrients are lacking in the staple diet.  
  protein-energy malnutrition  
  Protein-energy malnutrition describes a range of clinical disorders. At one end of the spectrum lies kwashiorkor, which is caused by a quantitative and qualitative lack of protein in the diet, but where energy intake may be adequate. At the other end is marasmus, which is the result of a continual restriction of both energy and protein, as well as other nutrients. Both conditions arise as a result of poverty and ignorance concerning infant feeding practices, where breast feeding may have ended too early and unsuitable infant foods introduced.  
  As a result of protein-energy malnutrition there is a failure in the functioning of certain body organs and impairment of the immune system, a drastic alteration in body composition, and disorders of metabolism. If the disease is so severe as to warrant treatment in hospital, the prognosis of the patient is uncertain.  
  iodine deficiency  
  Low iodine intakes are one cause of endemic goiter, and cretinism also occurs in areas in which severe iodine deficiency has been prevalent for several generations. Endemic cretinism is known to occur in parts of Nepal, the Andes, the Democratic Republic of Congo (formerly Zaire), and New Guinea, and in some communities may affect 1–5% of the population. Prevention of endemic goitre and cretinism can be established by effective iodine prophylaxis. This can be achieved by iodinization of table salt or iodized oil injections.  
  iron deficiency anemia  
  Iron deficiency anemia, in which the red blood cells contain abnormally low amounts of hemoglobin, occurs in all countries of the world. In the Middle East, Africa, and Asia as much as 20% of the population is affected. It is still common in the developed world, particularly in women of childbearing age. Iron deficiency may be due to an iron-poor diet, poor absorption of the mineral due to disease, or an unreplaced loss of iron from menstruation or other blood loss.  




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  vitamin deficiencies  
  Vitamins can be found in a wide variety of dietary sources, and in developed countries deficiencies tend to be rare. However, this is not the case in developing countries, where insufficient food supplies combined with infectious diseases mean that vitamin deficiencies are a common occurrence.  
  Mental Disorders  
  Psychiatric disorders are a common, if somewhat stigmatized, problem. The main areas dealt with include:  
  • schizophrenia and other psychoses;  
  • mood disorders (bipolar disorders, depressive disorders, manic depression);  
  • anxiety disorders (panic disorders, phobias, obsessive-compulsive disorder, post-traumatic stress disorder);  
  • personality disorders.  
  Schizophrenia is a mental disorder, a psychosis of unknown origin, which can lead to profound changes in personality, behavior, and perception, including delusions and hallucinations. It is more common in males and the early-onset form is more severe than when the illness develops in later life. Modern treatment approaches include drugs, family therapy, stress reduction, and rehabilitation.  
  Schizophrenia implies a severe divorce from reality in the patient's thinking. Although the causes are poorly understood, it is now recognized as an organic disease, associated with structural anomalies in the brain. There is some evidence that early trauma, either in the womb or during delivery, may play a part in causation. There is also a genetic contribution.  
  There is an enormous intercountry variation in the symptoms of schizophrenia and in the incidence of the main forms of the disease, according to a 1997 report by U.S. investigators. Paranoid schizophrenia, characterized by feelings of persecution, is 50% more common in developed countries, whereas catatonic schizophrenia, characterized by total immobility, is six times more frequent in developing countries. Hebephrenic schizophrenia, characterized by disorganized behavior and speech and emotional bluntness, is four times more prevalent in developed countries overall but is rare in the United States.  
  Canadian researchers in 1995 identified a protein in the brain, PSA-NCAM, that plays a part in filtering sensory information. The protein is significantly reduced in the brains of schizophrenics, supporting the idea that schizophrenia occurs when the brain is overwhelmed by sensory information. In 1997, U.S. researchers linked schizophrenia to a mutation in the gene that codes for an acetylcholine receptor. The receptor, a7-nictotinic receptor, is also stimulated by nicotine.  
  The prevalence of schizophrenia in Europe is about 2–5 cases per 1,000 of the population.  
  Facts about schizophrenia—causes and symptoms, the different types of the disease, how it affects sufferers' family members, available treatments, and new developments. It includes a list of available support resources.  
  This is a mental disorder marked by delusions of grandeur or persecution. In popular usage, paranoia means baseless or exaggerated fear and suspicion.  
  In chronic paranoia, patients exhibit a rigid system of false beliefs and opinions, believing themselves, for example, to be followed by the secret police, to be loved by someone at a distance, or to be of great importance or in special relation to God. There are no hallucinations and patients are in other respects normal. In paranoid states, the delusions of persecution or grandeur are present but not systematized. In paranoid schizophrenia, the patient suffers from many unsystematized and incoherent delusions, is extremely suspicious, and experiences hallucinations and the feeling that external reality has altered.  
  Depression is an emotional state characterized by sadness, unhappy thoughts, apathy, and dejection. It is the most common reason in the U.K. for people consulting a general practitioner. After childbirth, postnatal depression is common. However, clinical depression, which is prolonged or unduly severe, often requires treatment, such as antidepressant medication, cognitive therapy, or, in very rare cases, electroconvulsive therapy (ECT), in which an electrical current is passed through the brain.  
  Periods of depression may alternate with periods of high optimism, over-enthusiasm, and confidence. This  
  Depression Central
  Jumping-off point for information on all types of depressive disorders and on their most effective treatment. This site is divided into many useful sections, including "bipolar disorder," "depression in the elderly," and "electroconvulsive therapy."  




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  is the manic phase in a disorder known as manic depression or bipolar disorder.  
  manic depression or bipolar disorder  
  This mental disorder is characterized by recurring periods of either depression or mania (inappropriate elation, agitation, and rapid thought and speech) in which a person switches repeatedly from one extreme to the other. Each mood can last for weeks or months. Typically, the depressive state lasts longer than the manic phase.  
  Sufferers may be genetically predisposed to the condition. Some cases have been improved by taking prescribed doses of lithium. Some manic-depressive patients have only manic attacks, others only depressive, and in others the alternating, or circular, form exists. The episodes may be of varying severity, from mild to psychotic (when the patient loses touch with reality and may experience hallucinations), and sometimes continue for years without interruption.  
  Long Term Pharmacotherapy of Depression
  Part of a collection of articles maintained by the British Medical Journal, this page features the full text of a April 18, 1998 editorial addressing the "importance of long term psychological and pharmacological treatment."  
  Anxiety is a subjective experience of fear and apprehension accompanied by an overwhelming feeling of impending doom. It is commonly associated with symptoms such as breathlessness, sweating, palpitations, nausea, and chest pain.  
  obsessive-compulsive disorder  
  This is an anxiety disorder that manifests itself in the need to check constantly that certain acts have been performed "correctly." Sufferers may, for example, feel compelled to repeatedly wash themselves or return home again and again to check that doors have been locked and appliances switched off. They may also hoard certain objects and insist in these being arranged in a precise way or be troubled by intrusive and unpleasant thoughts. In extreme cases normal life is disrupted through the hours devoted to compulsive actions. Treatment involves cognitive therapy and drug therapy with serotonin-blocking drugs such as Prozac.  
  A phobia is an excessive irrational fear of an object or situation-for example, agoraphobia (fear of open spaces and crowded places), acrophobia (fear of heights), and claustrophobia (fear of enclosed places). Behavior therapy is one form of treatment.  
  personality disorders  
  This involves a maladjusted, often antisocial pattern of behavior that is usually well in evidence by the teenage years. The person concerned lacks insight and tends to be a liability (if not a danger) to himself and others. The condition remains curiously intractable, but some people mature out of their maladaptive behavior and become better adjusted in middle life.  
  Psychopathy is a personality disorder characterized by chronic antisocial behavior (violating the rights of others, often violently) and an absence of feelings of guilt about the behavior. Because the term "psychopathy" has been misused to refer to any severe mental disorder, many psychologists now prefer the term "antisocial personality disorder," though this also includes cases in which absence or a lesser degree of guilt is not a characteristic feature.  
  Maternal and Fetal Health  
  complications of pregnancy and childbirth  
  Every day, at least 1,600 women die from the complications of pregnancy and childbirth. A high proportion of these deaths—almost 90%—occur in Asia and sub-Saharan Africa; approximately 10% in other developing regions; and less than 1% developed countries.  
  Maternal mortality is about 18 times higher in the developing world than in developed countries. These maternal mortality ratios reflect a woman's risk of dying each time she becomes pregnant; because women in developing countries bear many children and obstetric care is poor, their lifetime risk of maternal death is much higher—approximately 40 times higher than in the developed world.  
  In addition to maternal mortality, half of all perinatal deaths are due primarily to inadequate maternal care during pregnancy and infant delivery. Each year, 8 million neonatal deaths and stillbirths occur, largely the result of those factors that also cause the death and disability of their mothers—poor maternal health, poor hygiene and inappropriate management of infant delivery, as well as lack of neonatal care.  
  abortion Each year, about 20 million unsafe abortions occur around the world, resulting in some 80,000 maternal deaths, and hundreds of thousands of disabilities. Most of these deaths take place in developing countries. Unsafe abortion accounts for at least 13% of global maternal mortality, and in some countries is the most common cause of maternal mortality and morbidity.  




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Fear Name of phobia
Animals zoophobia
Bacteria bacteriophobia, bacillophobia
Beards pogonophobia
Bees apiphobia, melissophobia
Being alone monophobia, autophobia, eremophobia
Being buried alive taphophobia
Being seen by others scopophobia
Being touched haphephobia, aphephobia
Birds ornithophobia
Blood h(a)ematophobia, hemophobia
Blushing ereuthrophobia, e(y)rythrophobia
Books bibliophobia
Cancer cancerophobia, carcinophobia
Cats ailurophobia, gatophobia
Chickens alektorophobia
Childbirth tocophobia, parturiphobia
Children pediphobia
Cold cheimatophobia, frigophobia
Color chromatophobia, chromophobia, psychrophobia
Comets cometophobia
Computers computerphobia, cyberphobia
Contamination misophobia, coprophobia
Criticism enissophobia
Crossing bridges gephyrophobia
Crossing streets dromophobia
Crowds demophobia, ochlophobia
Darkness achulophobia, nyctophobia, scotophobia
Dawn eosophobia
Daylight phengophobia
Death, corpses necrophobia, thanatophobia
Defecation rhypophobia
Deformity dysmorphophobia
Demons demonophobia
Dirt mysophobia
Disease nosophobia, pathophobia
Disorder ataxiophobia
Dogs cynophobia
Drafts anemophobia
Dreams oneirophobia
Drinking dipsophobia
Drugs pharmacophobia
Duration chronophobia
Dust amathophobia, koniphobia
Eating phagophobia
Enclosed spaces claustrophobia
Everything pan(t)ophobia
Facial hair trichopathophobia
Failure kakorrphiaphobia
Fatigue kopophobia, ponophobia
Fears phobophobia
Feces coprophobia
Fever febriphobia
Fire pyrophobia
Fish ichthyophobia
Flying, the air aerophobia
Fog homichlophobia
Food sitophobia
Foreign languages xenoglossophobia
Freedom eleutherophobia
Fun cherophobia
Germs spermophobia, bacillophobia
Ghosts phasmophobia
Glass hyalophobia
God theophobia
Going to bed clinophobia
Graves taphophobia
Hair chaetophobia, trichophobia, hypertrichophobia
Heart conditions cardiophobia
Heat thermophobia
Heaven ouranophobia
Heights acrophobia, altophobia
Hell hadephobia, stygiophobia
Home domatophobia, oikophobia
Homosexuality homophobia
Horses hippophobia
Human beings anthrophobia
Ice, frost cryophobia
Ideas ideophobia
Illness nosemaphobia, nosophobia
Imperfection atelophobia
Infection mysophobia
Infinity apeirophobia
Injustice dikephobia
Inoculations, injections trypanophobia
Insanity lyssophobia, maniaphobia
Insects entomophobia
Itching acarophobia, scabiophobia
Jealousy zelophobia
Knowledge epistemophobia
Lakes limnophobia
Large objects macrophobia
Leaves phyllophobia
Left side levophobia
Leprosy leprophobia
Lice pediculophobia
Lightning astraphobia
Machinery mechanophobia
Many things polyphobia
Marriage gamophobia
Meat carnophobia
Men androphobia
Metals metallophobia
Meteors meteorophobia
Mice musophobia


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Fear Name of phobia
Mind psychophobia
Mirrors eisoptrophobia, catotrophobia
Money chrometophobia
Monsters, monstrosities teratophobia
Motion kinesophobia, kinetophobia
Music musicophobia
Names onomatophobia
Narrowness anginaphobia
Needles belonophobia
Night, darkness achluophobia
Noise phonophobia
Novelty cainophobia, cenotophobia, neophobia
Nudity gymnotophobia
Number 13 triskaidekaphobia, terdekaphobia
Odors osmophobia
Open spaces agoraphobia
Pain algophobia, odynophobia
Parasites parasitophobia
Physical love erotophobia
Pins enetophobia
Places topophobia
Pleasure hedonophobia
Pointed instruments aichmophobia
Poison toxiphobia, toxophobia, iophobia
Poverty peniaphobia
Precipices cremnophobia
Pregnancy maieusiophobia
Punishment poinephobia
Rain ombrophobia
Reptiles batrachophobia
Responsibility hypegiaphobia
Ridicule katagalophobia
Rivers potamophobia
Robbery harpaxophobia
Ruin atephobia
Rust iophobia
Sacred things hierophobia
Satan satanophobia
School scholionophobia
Sea thalassophobia
Semen spermatophobia
Sex genophobia
Sexual intercourse coitophobia
Shadows sciophobia
Sharp objects belonephobia
Shock hormephobia
Sin hamartiophobia
Sinning peccatophobia
Skin dermatophobia
Sleep hypnophobia
Small objects microphobia
Smell olfactophobia
Smothering, choking pnigerophobia
Snakes ophidiophobia, ophiophobia
Snow chionophobia
Soiling rypophobia
Solitude eremitophobia, eremophobia
Sound akousticophobia
Sourness acerophobia
Speaking aloud phonophobia
Speed tachophobia
Spiders arachn(e)ophobia
Standing stasiphobia
Standing erect stasibasiphobia
Stars siderophobia
Stealing kleptophobia
Stillness eremophobia
Stings cnidophobia
Strangers xenophobia
Strong light photophobia
Stuttering laliophobia, lalophobia
Suffocation anginophobia
Sun heliophobia
Symbols symbolophobia
Taste geumaphobia
Teeth odontophobia
Thinking phronemophobia
Thrown objects ballistophobia
Thunder astraphobia, brontophobia, keraunophobia
Touch aphephobia, haptophobia, haphephobia
Travel hodophobia
Traveling by train siderodromophobia
Trees dendrophobia
Trembling tremophobia
Vehicles amaxophobia, ochophobia
Venereal disease cypridophobia
Void kenophobia
Vomiting emetophobia
Walking basiphobia
Wasps spheksophobia
Water hydrophobia, aquaphobia
Weakness asthenophobia
Wind ancraophobia
Women gynophobia
Words logophobia
Work ergophobia, ergasiophobia
Worms helminthophobia
Wounds, injury traumatophobia
Writing graphophobia





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Maternal Deaths, Maternal Mortality Ratio, and Lifetime Risk of Maternal Death, by Region
Source: WHO and Unicef
Annual number of maternal deaths
Maternal mortality ratio1
Lifetime risk of maternal death (one in:)
Developed countries
Developing countries
Eastern Africa
Middle Africa
Northern Africa
Southern Africa
Western Africa
Eastern Asia
South-central Asia
Southeastern Asia
Western Asia
Eastern Europe
Latin America and the Caribbean
Central America
South America
North America
1 Maternal Mortality Ratio (MMR) = total number of maternal deaths for every 100, 000 live births. This ratio measures the risk of death a woman faces each time she becomes pregnant.
2 Australia, New Zealand, and Japan have been excluded from the regional; totals, but are included in the total for developed countries.


Unsafe Abortion: Regional Estimates of Mortality and Risk of Death
Source: World Health Organization
No. of maternal deaths due to unsafe abortion
Risk of dying after unsafe abortion (one in:)
Maternal deaths due to unsafe abortion (%)
Latin America and the Caribbean
1 Japan, Australia, and New Zealand excluded.


  Unsafe abortion is now recognized by many governments as a major public health issue.  
  Complementary Therapy  
  The term "complementary therapy" is used to encompass any practice or system of beliefs about treatment that is not included in what is generally understood as Western scientific medicine. Science and much of Western medical practice is incompatible with many of the practices of complementary therapy, as such practices do not often have a scientific basis, though this should not be seen as an obstacle to its understanding and acceptance. Practitioners of complementary therapy are seeing their role increasingly as offering something that Western scientific medicine does not, and something that adds to it without denying that scientific medicine has an essential role.  
  Medical intervention is restricted to qualified  




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Diseases and Disorders
Source: World Health Organization
Group Subgroup Examples
Diseases of the blood and blood-forming organs and disorders involving the immune mechanism nutritional anemias

hemolytic anemias
aplastic and other anemias

coagulation defects, purpura, and other hemorrhagic conditions
other diseases of blood and blood-forming organs
iron deficiency anemia, vitamin B12 deficiency anemia
thalassemia, sickle-cell disorder
acquired pure red cell aplasia, acute posthemorrhagic anemia
hereditary factor VIII deficiency, hereditary factor IX deficiency
agranulocytosis, diseases of spleen, methaemoglobinemia
Endocrine and metabolic diseases disorders involving the immune mechanism disorders of thyroid gland

Disorders of glucose regulation and pancreatic internal secretion
disorders of other endocrine glands

metabolic disorders
immunodeficiencies, sarcoidosis
iodine-deficiency syndrome, hypothyroidism, thyroditis
non-diabetic hypoglycemic coma

hyper- or hypofunction of pituitary gland, Cushing's syndrome, diseases of thymus, polyglandular dysfunction
lactose intolerance, cystic fibrosis, amyloidosis
Diseases of the nervous system inflammatory diseases of the central nervous system systemic atrophies primarily affecting the central nervous system
extrapyramidal and movement disorders
other degenerative metabolic disorders of the nervous system
demyelinating diseases of the central nervous system episodic and paroxysmal disorders

nerve, nerve root, and plexus disorders

polyneuropathies and other disorders of the perypheral nervous system
diseases of myoneural junction and muscle
cerebral palsy and other paralytic syndromes

other disorders of the nervous system
bacterial meningitis, encephalitis, myelitis, encephalomyelitis
Huntington's disease, hereditary ataxia
Parkinson's disease, dystonia
Alzheimer's disease

multiple sclerosis
epilepsy, migraine, other headache syndromes, sleep disorders
of trigeminal nerve, facial, cranial nerve, mononeuropathies
hereditary, idiopathic, inflammatory

myasthenia gravis
infantile cerebral palsy, hemiplegia, paraplegia,
hydrocephalus, toxic encephalopathy
Diseases of the eye and adnexa disorders of eyelid, lacrimal system, and orbit
disorders of conjunctiva
disorders of sclera, cornea, iris, and ciliary body
disorders of lens
disorders of choroid and retina
disorders of vitreous body and globe
disorders of optic nerve and visual pathways
disorders of ocular muscles, binocular movement, accommodation, and refraction
visual disturbances and blindness
other disorders of eye and adnexa
hordeolum and chalazion
keratitis, iridocyclitis
retinal detachments and breaks
optic neuritis

low vision
Diseases of the ear and mastoid process diseases of external ear
diseases of middle ear and mastoid

diseases of inner ear
other disorders of ear
otitis externa
mastoiditis, ostitis media, disorders of tympanic
otalgia and effusion of ear, hearing loss


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Group Subgroup Examples
Diseases of the respiratory system acute upper respiratory infections

influenza and pneumonia
other acute lower respiratory infections
other diseases of upper respiratory tract

chronic lower respiratory diseases

lung diseases due to external agents

other respiratory diseases primarily affecting the interstitium
suppurative and necrotic conditions of lower respiratory tract
other diseases of pleura
other diseases of the respiratory system
acute nasopharyngitis (common cold), acute sinusitis, acute laryngitis, acute obstructive laryngitis (croup)
influenza, pneumonia
acute bronchitis
chronic rhinitis, chronic sinusitis, nasal polyp, chronic laryngitis
bronchitis (non-acute and non-chronic), emphysema, asthma
coalworker's pneumoconiosis; pneumoconiosis due to asbestos, other mineral fibers, dust containing silica; conditions due to inhalation of chemicals, gases, fumes, and vapors
pulmonary edema

abscess of lung and mediastinum, pyothorax

pleural effusion, pleural plaque
respiratory failure, not elsewhere classified
Diseases of the digestive system diseases of oral cavity, salivary glands, and jaws

diseases of esophagus, stomach, and duodenum

diseases of appendix

noninfective enteritis and colitis
other diseases of intestines
diseases of peritoneum
diseases of liver

disorders of gallbladder, biliary tract, and pancreas other diseases of the digestive system
dental caries, gingivitis and periodontal diseases, stomatitis
esophagitis, gastric ulcer, duodenal ulcer, peptic ulcer, dyspepsia
acute appendicitis
inguinal, femoral, umbilical, ventral, diaphragmatic hernia
Crohn's disease
irritable bowel syndrome
alcoholic liver disease, toxic liver disease, fibrosis and cirrhosis of liver
cholelithiasis, cholecystitis, pancreatitis intestinal malabsorption
Diseases of skin and subcutaneous tissue infections of skin and subcutaneous tissue

bullous disorders
dermatitis and eczema
papulosquamous disorders
urticaria and erythema
radiation-related disorders of the skin and subcutaneous tissue
disorders of skin appendages
impetigo, cutaneous abscess, furuncle, carbuncle, cellulitis
dermatitis, eczema, pruritus
psoriasis, pityriasis rosea, lichen planus
urticaria, erythema
sunburn, radiothermatitis

nail disorders, hair disorders, acne, rosacea, sweat disorders
Diseases of the musculoskeletal system and connective tissue other disorders of skin and subcutaneous tissue


systemic connective tissue disorders
soft tissue disorders
osteopathies and chondropathies

other disorders of the musculoskeletal system and connective tissue
vitiligo, seborrheic keratosis, corns and callosities, lupus erythematosus
infectious arthropathies, inflammmatory
polyarthropathies, arthrosis
polyarteritis nodosa, dermatopolymyositis deforming dorsopathies, spondylopathies of muscles, of synovium and tendon
disorders of bone density and structure
(including osteoporosis); osteomyelitis, osteonecrosis
other acquired deformities, postprocedural disorders, not elsewhere classified


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Group Subgroup Examples
Diseases of the genito-urinary system glomerular diseases
renal tubulo-interstitial diseases
renal failure
other disorders of kidney and ureter

other diseases of the urinary system
diseases of male genital organs

disorders of breast
inflammatory diseases of female pelvic organs
noninflammatory disorders of female genital
other disorders of the genito-urinary system
nephritis syndrome
acute, chronic
calculus of kidney, ureter, lower urinary tract
unspecified contracted kidney, small kidney of
unknown cause
cystitis, urethritis
disorders of prostate, male infertility, disorders of
benign mammary dysplasia, hypertrophy of breast
uterus, cervix uteri, vagina, vulva
endometriosis, conditions related to menstruation
and menstrual cycle, female infertility
postprocedural disorders, not elsewhere classified
Congenital malformations, deformations, and chromosomal abnormalities congenital malformations of the nervous system
congenital malformations of eye, ear, face, and
congenital malformations of the circulatory
congenital malformations of the respiratory
cleft lip and cleft palate
other congenital malformations of the digestive
congenital malformations of genital organs

congenital malformations of the urinary system
congenital malformations and deformations of
the musculoskeletal system
other congenital malformations
chromosomal abnormalities, not elsewhere classified
anencephaly, microcephaly, spina bifida
anophthalmos, micro- and macrophthalmos
of cardiac chambers, connections, septa; of great
arteries; of great veins
of nose, larynx, trachea, bronchus, lung

either or both
of tongue, mouth, esophagus, intestines

of ovaries, fallopian tubes, uterus, cervix, female genitalia; undescended testicle, hypospadias, malformations of male genitalia; indeterminate sex and pseudohermaphroditism
renal agenesis, cystic kidney disease
polydactyly, syndactyly, osteochondrodysplasias

congenital ichthyosis, epidermolysis bullosa
Down's syndrome, Edward's syndrome, Patau's syndrome, Turner's syndrome
Symptoms, signs, and abnormal clinical and laboratory findings, not elsewhere classified symptoms and signs involving the circulatory
and respiratory systems
symptoms and signs involving the digestive
system and abdomen
symptoms and signs involving the skin and
subcutaneous tissue
symptoms and signs involving the nervous and
musculoskeletal systems
symptoms and signs involving the urinary
symptoms and signs involving cognition,
perception, emotional state, and behavior

symptoms and signs involving speech and voice

general symptoms and signs
gangrene, not elsewhere classified; cardial
murmurs; cough; pain in throat and chest
abdominal and pelvic pain, nausea and vomiting,
heartburn, dysphagia, fecal incontinence
rash, localized swelling; disturbances of skin
abnormal involuntary movements, lack of coordination
unspecified urinary incontinence, retention of urine
somnolence, stupor, and coma; dizziness and giddiness; disturbances of smell and taste; symptoms and signs involving appearance dyslexia, speech disturbances (not elsewhere classified)
fever, headache, malaise and fatigue, senility, syncope and collapse, enlarged lymph nodes, lack of expected physiological development, other general symptoms and signs, unknown and unspecified causes of morbidity


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Group Subgroup Examples
  abnormal findings on examination of blood, without diagnosis

abnormal findings on examination of urine, without diagnosis
abnormal findings on examination of other body fluids, substances and tissues, without diagnosis
abnormal findings on diagnostic imaging and in function studies, without diagnosis
ill-defined and unknown causes of mortality injuries to the head
abnormalities of plasma viscosity, red blood cells, white blood cells (not elsewhere specified), elevated blood glucose levels, findings of drugs or other substances not normally found in blood isolated proteinuria, glycosuria

findings in cerebrospinal fluid and tissues

imaging of central nervous system, lung, breast

sudden infant death syndrome
includes, where applicable, superficial injury, open wound, fracture, dislocation, sprain, strain, crushing injury, injury to nerves in the area, injury to blood vessels in the area, traumatic amputation of (part of) organ or body part
Injury, poisoning, and certain other consequences of external causes injuries to the neck
injuries to the thorax
injuries to the abdomen, lower back, lumbar
spine, and pelvis
injuries to the shoulder and upper arm
injuries to the elbow and forearm
injuries to the wrist and hand
injuries to the hip and thigh
injuries to the knee and lower leg
injuries to the ankle and foot
injuries involving multiple body regions
injuries to unspecified part(s) of trunk, limb, or body region
effects of foreign body entering through natural orifice
burns and corrosions

poisoning by drugs, medicaments, and biological substances
toxic effects of substances chiefly unmedical as to source

other and unspecified effects of external causes

certain early complications of trauma
complications of surgical and medical care, not elsewhere classified

sequelae of injuries, of poisoning, and of other consequences of external causes

foreign body on external eye, in ear, in respiratory tract
of external body surface; confined to eye and internal organs; of multiple and unspecified body regions
superficial; with tissue necrosis
poisoning (various forms)

alcohol, organic solvents, corrosive substances, soaps and detergents, metals, pesticides, venomous animals
hypothermia, asphyxiation, maltreatment
syndromes, unspecified effects of radiation
complications not elsewhere classified
following procedures, implants, prosthetic devices, failure and rejection of transplanted organs and tissues, complications peculiar to reattachment and amputation
sequela of conditions as above


  medical practitioners in many Western countries and a significant proportion of them use complementary therapy. Not all complementary practitioners are regulated and this has caused concern as complementary therapy grows in popularity. However, organizations concerned with the training and registration of complementary practitioners have developed at a rapid rate recently to meet the growing demands of the public  




Page 533
  for a pluralist, holistic, effective, and safe approach to health care.  
  The roots of homeopathy lie in the work of Samuel Hahnemann (1755–1843), an 18th-century German physician. The brutalities of medical practice, which included purging, bleeding, and the use of poisons, were instrumental in his decision to explore other avenues in which he could use his skills. He was prompted to investigate the use of cinchona bark in the treatment of fever while he was working on a Materia Medica. Cinchona bark produced many of the symptoms associated with fever without inducing pyrexia. This led to him to speculate that a substance that was effective against a disease would produce symptoms resembling those of that disease if it was given to a healthy person.  
  Homeopathy recognizes a need for balance and harmony. Disturbances in the harmony of the body due to illness can precede the appearance of symptoms as the body reacts to the illness. Symptoms of the same illness differ between individuals, and the establishment of a detailed profile of the patient and a complete symptom picture are an essential part of the diagnosis. Homeopathic remedies are intended to stimulate the resources of the body to restore its natural harmony, following Hahnemann's principle that the appropriate treatment is one that produces the same symptoms in a healthy person. Many of these principles pose a problem to the scientist, but the greatest obstacle to scientific acceptance is the observation that homeopathic remedies become more potent when subject to serial dilution and mechanical shock. Theories have been developed in an attempt to explain why more dilute preparations are more powerful, but none of these have yet been proven.  
  herbal medicine  
  A wide range of medical practices that use unrefined and refined plant materials for treatment is encompassed by the term ''herbal medicine." They do not necessarily have a common belief system and they range from traditional herbal medicine to many ethnic medical systems, such as Chinese and Ayurvedic medicine.  
  Plants were used medicinally in China, Egypt, Greece, Rome, and other ancient civilizations up to 5,000 years ago. The central position of herbalism in health care was challenged by changes in medical thinking in Renaissance Europe, and by the consequent emphasis on the management of symptoms with specific remedies by the emerging medical establishment.  
  Samuel Thomson, an American physician, documented much of this early herbalist knowledge in the early 19th century, and he is now credited as the founder of Western herbal medicine. He developed a theory resembling that of the four humors, in which life and health were represented by heat; illness and death by cold; motion by air; and energy or life force by fire. He believed that the fever associated with infection was a healthy sign and, unlike his contemporaries, he wanted to facilitate it rather than to suppress it. He considered that coughing, vomiting, and diarrhea were healthy signs of the body removing toxins.  
  The underlying belief in herbalism is that health depends on maintaining the natural state of the body. The natural state of the body, or "vital pulse," is represented by the rhythmic variation in tissue and cell activity, which protects, regulates, and renews the body. An herbal remedy is a preparation of the entire plant rather than an active ingredient extracted from it. The constituent components may have many different activities that restore the balance of the body, which is lost with the onset of illness. They are not specific for a particular symptom and they are thought to act by stimulating the natural defenses of the body and enhancing the elimination of toxins. Attention to diet is often used as an adjunct to treatment by herbalists.  
  The therapeutic use of volatile oils can be traced back to the ancient civilizations of India, China, Egypt, Babylon, and Greece, and their use in medicine survived until challenged by the advent of scientific chemistry in the 17th century.  
  Aromatherapists believe that health depends on a balance of mental, emotional, and physical processes which is disturbed in illness. A holistic approach is taken to diagnosis and treatment. The volatile oils used in aromatherapy are complex mixtures of chemicals that occur naturally in plants. Specific disorders are treated with particular oils. They are believed to be absorbed through the skin or by inhalation before exerting their subtle effects on physical symptoms and emotional well being. The pleasant smell and application of the oils by massage can enhance the beneficial effects of aromatherapy through reduction of tension and pain, increased relaxation, and improved circulation. Aromatherapy is widely used as an adjunct to conventional care in patients who are terminally ill.  
  Traditional Chinese medicine is based on the fundamental principle that a life force known as qi flows around the body in 12 channels known as meridians. The flow of qi is important for good health. The balance between yin and yang, qualities possessed by all  




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  things including the internal functions and processes of the body and the meridians, is also vital to health. Yin is cold, dark, passive, and negative; yin organs include the heart, spleen, kidney, and liver. Yang is warm, light, active, and positive; yang organs include the small intestine, stomach, bladder, and gall bladder. Illness occurs when either yin or yang is dominant, and treatment helps to restore their balance.  
  Thorough introduction to the alternative world of acupuncture with descriptions of the main notions and powers of herbology, yoga, Qi Gong, and Chinese nutrition. Consumers are given access to lists of practitioners and an extensive section on acupuncture research. Practitioners can browse through journal listings and the latest industry news and announcements.  
  Acupuncture is one form of treatment used in traditional Chinese medicine. It involves the insertion of fine needles into the skin at particular points on the body to correct the imbalances between yin and yang. There are about 2,000 acupoints that lie on the meridians through which qi flows. The imbalance between yin and yang may be associated with many factors, such as stress, emotion, diet, or injury, and these are considered in conjunction with the medical history of the patient, and examination of the 12 pulses and the condition of the tongue before a diagnosis is made. The acupoints to be stimulated are then selected and needles are inserted to a depth of about 1/4 of an inch (6 mm) and rotated. The direction of insertion and rotation of the needles regulates the flow of qi and the collection or dispersion of energy.  
  Acupuncture can be used to treat a wide range of acute and chronic illnesses, such as pain, anxiety, asthma, migraine, menstrual disorders, and gastrointestinal complaints. It can also be used as an aid to dieting and giving up smoking.  
  Osteopaths perceive the function of muscles and the skeletal system to be central to a range of health problems. Osteopathy was conceived as a system of diagnosis and treatment by Andrew Taylor Still in the United States in the 19th century. He believed that a lack of balance in the mechanical functioning of the body, such as muscle groups being too tense or joints moving incorrectly, may cause illness. He developed a range of manipulative techniques to correct the imbalances and claimed therapeutic success. These include massage, passive movement, and stretching of the limbs. Despite opposition from the medical profession, osteopathy has slowly achieved success because it can produce a dramatic improvement in disorders that are difficult to treat by conventional medicine, such as chronic back pain and sciatica.  
  These are just a few of the more popular forms of complementary therapy that are available today. There are many others: chiropractic, reflexology, and relaxation techniques such as hypnotherapy, to name but a few.  
  Osteopathic Home Page
  Well organized site, from the American Association of Osteopathy, dedicated to increasing public understanding of osteopathy. The theory behind the osteopaths' belief in the body's innate healing power and some of the healing techniques are fully explained. There is also an account of the origins and development of osteopathy and a selection of case histories attest to its success.  




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  Health and Disease Chronology  
Health and Disease Chronology
c. 2800 B.C. Chinese emperor Shen Nong describes the therapeutic powers of numerous medicinal plants.
c. 2500 B.C. The practice of acupuncture is developed in China.
c. 1600 B.C. The Edwin Smith papyrus is written. The first medical book, it contains clinical descriptions of the examination, diagnosis, and treatment of injuries, and reveals an accurate understanding of the workings of the heart, stomach, bowels, and larger blood vessels. The papyrus is named for U.S. scientist Edwin Smith, a pioneer in the study of Egyptian science who acquired it in Luxor, Egypt, in 1862.
c. 1122 B.C. Smallpox is first described, in China. Pharaoh Ramses V, who dies in 1157 B.C., is considered the first known victim of the disease.
c. 650 B.C. Tuberculosis, leprosy, and gonorrhea are first described with accuracy.
437 B.C. The world's first hospital is established in Ceylon.
c. 400 B.C. Greek physician Hippocrates of Cos begins the corpus of the Hippocratic Collection of about 70 medical treatises which cover topics such as epidemics and epilepsy. There is no evidence that he wrote any of them himself, but by recognizing that disease has natural causes he begins the science of medicine.
c. 200 B.C. The Greek physician Aretaeus of Cappadocia describes manic-depressive psychosis.
c. 90 B.C. The Roman scholar Marcus Terentius Varro writes that disease is caused by the entry of imperceptible particles into the body—the first enunciation of germ theory.
180 The Greek physician Claudius Galen, practising at Rome, writes Methodus medendi/Method of Physicians, a medical textbook that will become the ultimate authority for medieval medicine.
900 The Muslim physician al-Razi describes diseases such as plague, consumption, smallpox, and rabies.
1443 Quarantine laws are introduced in England for the first time.
1489 The first major typhus epidemic in Europe occurs when Spanish soldiers returning form Cyprus introduce the disease.
1493 Syphilis appears in Europe for the first time, brought back from South America by sailors returning with the explorer Christopher Columbus. The disease is first reported in Barcelona, Spain.
1598 The physician known as G. W. publishes The Cure of the Diseased in Remote Regions, the earliest treatise on tropical medicine.
1601 Captain James Lancaster of the East India Company provides his crew with lemon juice and citrus fruits, avoiding an outbreak of scurvy, the deficiency disease that devastates the crews of other ships on his trade mission.
1625 German chemist Johann Glauber prepares hydrochloric acid by the action of sulfuric acid on common salt. He discovers the laxative properties of the byproduct, sodium sulfate, and markets it as a paten medicine, Glauber's salt, or sal mirabile.
1635 French physician Duterte describes yellow fever for the first time, during an outbreak on the islands of St. Kitts and Guadeloupe.
1642 Seville physician Pedro Barba recounts his use of "Peruvian bark," a source of quinine, for treating the Countess of Chinchou's malaria.
1650 English physician Fracis Glisson writes his Treatise on Rickets, a detailed clinical description of rickets.
1659 Typhoid fever is given a detailed description for the first time by British physician Thomas Willis.
1665 The last major outbreak of the Black Death (a form of bubonic plague) affects London, England, in an epidemic known as the "Great Plague," which reaches a peak in September, and around 70,000 people die.
1717 Lady Mary Wortley Montagu writes Inoculation Against Smallpox, reporting the method of immunization known in the East for centuries and introducing the practice of inoculation for smallpox into England; the inoculation of the Princess of Wales makes it fashionable.
1736 North American physician William Douglass publishes the first clinical description of scarlet fever, in a paper on the outbreak that hit the city the previous year.
1761 English naturalist John Hill writes that excessive use of snuff may lead to cancer; this is the first association of tobacco and cancer.
1763 English clergyman Edmund Stone describes the effective treatment of fever using willow bark, from which the active ingredient of aspirin is later derived.
1768 English physician William Heberden gives a full and correct clinical description of angina pectoris as pains of the chest precipitated by effort and originating form the heart.
1775 The first evidence that environmental and occupational factors can cause cancer is provided by English surgeon Percivall Pott, who suggests that chimney sweeps' exposure to soot causes cancer of the scrotum and nasal cavity.
1783 English physician Thomas Cawley correctly diagnoses diabetes mellitus by demonstrating the presence of sugar in a patient's urine.
1796 English physician Edward Jenner performs the first vaccination against smallpox.
1800 Scottish chemist William Cruickshank purifies water by adding chlorine.





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1806 German chemist Friedrich Wilhelm Saturner isolates morphine—the first painkiller—from opium.
1816 French physician René Laënnec invents the stethoscope to detect cardiovascular diseases.
1817 English surgeon James Parkinson describes the central nervous system disorder now known as Parkinson's disease.
1818 French chemist Jean-Baptiste-André Dumas uses iodine to treat goiters.
1819 British surgeon James Blundell makes the first human-to-human blood transfusion. The patient survives for 56 hours.
1819 French physician Jean-Louis-Marie Poiseuille is the first to use a mercury manometer to measure blood pressure.
1820 French chemists Joseph Pelletier and Joseph-Bienaimé Caventou isolate the antimalarial drug quinine, as well as the other alkaloids brucine, cinchonine, colchicine, strychnine, and veratrine.
1832 English physician Thomas Hodgkin first describes the lymphatic cancer, Hodgkin's disease.
1832 French chemist Pierre-Jean Robiquet isolates the analgesic, codeine, from opium.
1835 English physician James Paget discovers the parasitic worm Trichina spiralis which causes trichinosis.
1838 Italian chemist R. Piria synthesizes salicylic acid, the basic ingredient in aspirin, from willow bark.
1840 German physician Gustav Jacob Henle suggests that infectious diseases are caused by living microscopic organisms.
1840 Swiss chemist Charles Choss demonstrates that calcium is needed for proper bone development.
1842 U.S. surgeon Crawford Williamson Long is the first to use ether as an anesthetic in an operation. He does not publish his findings until 1849.
1851–1854 Over 250,000 people (approximately 2% of the population) die from tuberculosis in Britain.
1852 German physician Karl von Vierordt develops a method of counting red blood cells that becomes important in diagnosing anemia.
1853 Nearly 8,000 die in a yellow fever epidemic in New Orleans, Louisiana.
Nov 1854 English nurse Florence Nightingale arrives in Scutari, Ottoman Empire, and introduces sanitary measures in an effort to reduce deaths from cholera, dysentery, and typhus during the Crimean War.
1856 German scientist Theodore Bilharz discovers the parasitic worm that causes schistosomiasis (bilharzia).
1860 French physician Etienne Lancereaux suggests that diabetes is due to a disorder of the pancreas.
c. 1860 French chemist and microbiologist Louis Pasteur develops the process of pasteurization: sterilizing milk and other beverages by heating to a high temperature for a few minutes to kill microorganisms.
1861 Pasteur develops the germ theory of disease.
1863 French parasitologist Casimir-Joseph Davaine shows that anthrax is due to the presence of rodlike microorganisms in the blood. It is the first disease of animals and humans to be shown to be caused by a specific microorganism.
1863 French physiologist Etienne-Jules Marey invents the sphygmomanometer to record blood pressure graphically. It is still used today.
Aug 12, 1865 English surgeon Joseph Lister first uses phenol (carbolic acid) as an antiseptic during surgery, to kill germs.
1869 Norwegian physician Gerhard Henrik Armauer Hansen discovers the leprosy bacillus Mycobacterium leprae.
1871 German surgeon F. Steiner is the first to use electrical cardiac stimulation to successfully restart a patient's heart.
1873 English physician William Budd publishes Typhoid Fever, Its Nature, Mode of Spreading, and Prevention, in which he establishes the infectious nature of the disease.
1877 British physician Patrick Manson shows how insects can be the carriers of infectious diseases, and demonstrates that the embryo of the Filaria worm, which causes elephantiasis, is transmitted by mosquito.
1879 Pasteur discovers that chickens infected with weakened cholera bacteria are immune to the normal form of the disease. It leads to the development of vaccines.
1880 Pasteur discovers the bacterial genus Streptococcus that causes diseases such as scarlet fever and rheumatic fever.
1880 French pathologist Alphonse Laveran discovers the malaria parasite, in Algeria.
1880 German bacteriologist Karl Joseph Eberth discovers the Salmonella typhü bacteria responsible for typhoid.
May 5, 1881 Pasteur vaccinates sheep against anthrax. It is the first infectious disease to be treated effectively with an antibacterial vaccine, and his success lays the foundations of immunology.
1881 Austrian surgeon Theodor Christian Albert Billroth initiates modern abdominal surgery by removing the cancerous lower part of a patient's stomach.
1881 U.S. Army physician George Miller Sternberg discovers the bacillus responsible for pneumonia.
March 24, 1882 German physician Robert Koch announces the discovery of Mycobacterium tuberculosis, the





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  bacillus responsible for tuberculosis. This is the first time a microorganism has been definitively associated with a human disease.
1883 Koch discovers preventive inoculation against anthrax.
1883 German bacteriologists Edwin Klebs and Friedrich August Johannes Löffler discover Corynebacterium diptheriae, the diphtheria bacillus.
1883 Koch discovers the cholera bacillus.
Nov 25, 1884 German-born British surgeon Rickman John Godlee performs the first operation to remove a brain tumor.
1884 German physician Arthur Nikolaier discovers the tetanus bacillus, Clostridium tetani.
July 6, 1885 Pasteur develops a vaccine against rabies and uses it to save the life of a young boy, Joseph Meister, who has been bitten by a rabid dog.
1889 German physiologists Oskar Minkowski and Joseph von Mering remove the pancreas from a dog, which then develops diabetic symptoms. It leads them to conclude that the pancreas secretes an antidiabetic substance, which is now known as insulin.
1891 German medical scientist Paul Ehrlich treats malaria with methylene blue. Its use marks the beginning of chemotherapy.
July 10, 1893 U.S. surgeon Daniel Hale Williams performs the first open-heart surgery, on a patient who has been wounded by a knife. The patient lives for another 20 years.
1894 During an epidemic of bubonic plague in Hong Kong, Japanese bacteriologist Shibasaburo Kitasato and Swiss bacteriologist Alexandre Yersin, simultaneously and independently, discover the bacillus Yersinia pestis which is responsible for the plague.
1895 Belgian bacteriologist Jules Bordet discovers antibodies.
1895 The protozoa Trypanosoma gambiense is discovered to be the cause of African sleeping sickness.
1897 British bacteriologist Ronald Ross discovers the malaria parasite in the gastrointestinal tract of the Anopheles mosquito, and realizes that the insect is responsible for the transmission of the disease.
1897 English bacteriologist Almroth Edward Wright introduces a vaccine against typhoid. It is successfully tested on 3,000 troops sent to India.
1898 Martinus Willem Beijerinck identifies the first virus; it is the cause of tobacco mosaic disease in plants.
1900 U.S. army pathologist Walter Reed establishes that yellow fever is caused by the bite of an Aëdes aegypti mosquito infected with the yellow fever parasite. His discovery leads to the creation of a vaccine and makes possible the completion of the Panama Canal.
1901 Dutch physician Gerrit Grijns demonstrates that beriberi is caused by a nutritional deficiency of vitamin B1.
c. 1901 British soldiers are immunized against typhoid fever during the Boer War.
1903 German surgeon Georg Clems Perthes discovers that X-rays inhibit the growth of cancerous tumors and suggests they be used as a treatment.
1903 In New York, NY, a cook called Mary Mallon—"Typhoid Mary"—is discovered to be a carrier of typhoid, unwittingly carrying and spreading the diseases through handling food.
c. 1905 English biochemist Frederick Gowland Hopkins shows that the amino acid tryptophan and other essential amino acids cannot be manufactured from other nutrients but must be supplied in the diet.
1906 Belgian bacteriologists Jules Bordet and Octave Gengou discover the bacterium responsible for whooping cough, Bordetella pertussis.
1906 English biochemist Frederick Gowland Hopkins suggests that necessary "accessory factors (Vitamins) are contained in foods in addition to carbohydrates, fats, minerals, and water.
1910 U.S. physician James Herrick is the first to describe the genetic disease sickle-cell anemia.
1912 U.S. entomologist Leland Ossian Howard, publishes The House Fly, Disease Carrier, in which he identifies the common housefly as a major carrier of disease.
1912 U.S. physician James Herrick is the first to describe a coronary thrombosis—a blood clot in the coronary artery that causes damage to the heart (heart attack).
1913 German bacteriologist Emil von Behring introduces a toxin–antitoxin vaccine against diphtheria.
1914 Polish–American biochemist Casimir Funk isolates vitamin B, a vital discovery in the treatment of beriberi.
1918 English pharmacologist Edward Mellanby discovers that a vitamin (vitamin D) in cod-liver oil cures rickets.
1921 Canadian physiologists Frederick Banting, Charles Best, and John James MacLeod isolate insulin. A diabetic patient in Toronto, Canada, receives the first insulin injection.
1923 French bacteriologists Albert Calmette and Camille Guérin develop the tuberculosis vaccine, known as Bacillus Calmette-Guérin (BCG), and use it to vaccinate newborns at a hospital in Paris, France.
1923 U.S. physicians George and Gladys Dick isolate the microorganism responsible for scarlet fever (Streptococcus pyogenes) and develop an antitoxin.
1926 U.S. biochemist Elmer McCollum isolates vitamin D and uses it to successfully treat rickets.
1926 U.S. physicians George Richards Minot and William Parry Murphy use raw-liver extract for





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  treating the previously fatal disease pernicious anemia.
1928 Greek-born U.S. physician George Papanicolaou develops the Pap smear to test for uterine cancers.
1928 Scottish bacteriologist Alexander Fleming discovers penicillin when he notices that the mold Penicillium notatum, which has invaded a culture of staphylococci, inhibits the bacteria's growth.
1932 English physician Cecily Williams describes the protein deficiency disease kwashiorkor.
1933 Austrian-born German organic chemist R. Kuhn, Hungarian-born U.S. biochemist A. von Szent-Györgyi, and J Wagner-Jauregg discover vitamin B2 (riboflavin) in Hungary.
1933 Swiss biochemist Paul Karrer establishes the structure of vitamin A (retinol) and U.S. biologist George Wald demonstrates its important in preventing night blindness.
1937 French microbiologist Max Theiler develops a vaccine against yellow fever; it is the first antiviral vaccine.
1937 U.S. biochemist Conrad Arnold Elvehjem finds that vitamin B3 (niacin) prevents pellagra, a vitamin deficiency disease.
1938–1940 Five independent researchers isolate and synthesize vitamin B6 in Germany.
1939 U.S. microbiologist René J. Dubos is the first to search systematically for, and discover, natural antibiotics. He looks for soil bacteria that kill other bacteria and discovers the antibiotics gramicidin and tyrocidine.
1942 French physician André Loubatière leads the development of oral drugs for diabetics with his discovery that sulfa drugs lower blood sugar levels.
1943 U.S. biologist Selman A Waksman discovers the antibiotic streptomycin, which is used as a treatment for tuberculosis; he coins the term "antibiotic."
1944 Swiss pharmacologist Daniel Bovet discovers pyrilamine, the first antihistamine.
Oct 1945 The Food and Agriculture Organization (FAO) is established, the first of the UN's specialized agencies. Its objective is to eliminate hunger and improve nutrition worldwide.
1945 U.S. physician Alton Ochsner points to the relationship between cigarette smoking and lung cancer.
c. 1945 The first effective vaccine against influenza is developed.
1946 Penicillin is synthesized by U.S. chemist Vincent du Vigneaud.
1947 The poliomyelitis virus is isolated by U.S. physician Jonas E Salk.
July 5, 1948 The British National Health Service comes into effect.
1948 British biochemist Dorothy Hodgkin analyses the complex structure of vitamin B12 and makes the first X-ray photographs of it.
1948 The World Health Organization (WHO) is established with its headquarters in Geneva, Switzerland; its aim is to improve world health conditions.
1948 U.S. chemist Karl Folkers and British chemist Alexander Todd isolate vitamin B12.
1949 British biochemist Dorothy Hodgkin works out the chemical structure of penicillin.
1949 Lithium is first used to treat mental patients.
1949 The antibiotic chloramphenicol (Chloromycetin) is introduced; it is the first effective treatment for typhoid fever.
1949 The antibiotic tetracycline is discovered.
May 6, 1953 U.S. physician John Gibbon performs the first successful open-heart operation. He uses a heart-lung machine to oxygenate the blood during the operation.
1957 Interferon, a natural protein that fights viruses, is discovered by Scottish virologist Alick Isaacs and Swiss virologist Jean Lindemann.
1959 French researcher Jérôme Lejeune discovers that Down's syndrome is due to an extra chromosome 21. It is the first chromosomal disorder discovered.
1963 U.S. surgeon James Hardy performs the first lung transplant.
1963 U.S. surgeon Thomas Starlz performs the first liver transplant.
1966 U.S. virologists Harry Meyer and Paul Parman develop a live virus vaccine for rubella (German measles), which reduces the incidence of the disease.
Dec 3, 1967 South African surgeon Christiaan Barnard performs the first heart transplant operation. The patient survives for 18 days.
1967 Greek-born U.S. neurologist George Cotzias begins to use L-dopa, a precursor of dopamine, to successfully treat patients with Parkinson's disease.
1967 U.S. surgeon Rene Favaloro develops the coronary bypass operation.
Sept 15, 1969 The world's first heart and lung transplant is performed at the Stanford Medical Center in California.
1973 U.S. biochemists Stanley Cohen and Herbert Boyer develop the technique of recombinant DNA (deoxyribonucleic acid). Strands of DNA are cut by restriction enzymes from one species and then inserted into the DNA of another; this marks the beginning of genetic engineering.
1976 The first oncogene (cancer-inducing gene) is discovered by U.S. scientists Harold E. Varmus and J. Michael Bishop.
1977 Two homosexual men in New York, NY, are diagnosed as having the rare cancer Kaposi's sarcoma. They are later thought to be the first victims of AIDS.
May 1980 The World Health Organization announces the eradication of smallpox.





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1981 The U.S. Food and Drug Administration grants permission to Eli Lilley and Co. to market insulin produced by bacteria, the first genetically engineered product to go on sale.
Oct 1983 U.K. and U.S. studies indicate that long-term use of oral contraceptives may increase the risk of breast and cervical cancer.
1983 U.S. medical researcher Robert Gallo at the U.S. National Cancer Institute, Maryland, and French medical researcher Luc Montagnier at the Pasteur Institute in Paris, France, isolate the virus thought to cause AIDS; it becomes known as the HIV virus (human immunodeficiency virus).
1984 U.K. researchers develop the first vaccine against leprosy.
1985 An epidemic of bovine spongiform encephalopathy (BSE) is reported in beef cattle in Britain; it is later traced to cattle feed containing sheep carcasses infected with scrapie; in following years there are fears that beef consumption could lead to Creutzfeld-Jakob disease in humans.
1985 Researchers locate gene markers on chromosomes for cystic fibrosis and polycystic kidney disease.
1985 Screening blood donations for the AIDS virus begins in Britain.
1985 U.S. researcher Steven Rosenberg discovers interleukin 2, a crucial protein in the immune system involved in the activation of lymphocytes; researchers soon begin experimenting on its anticancer properties.
Dec 17, 1986 British surgeons John Wallwork and Roy Calne perform the first triple transplant—heart, lung, and liver.
March 20, 1987 The AIDS treatment drug AZT is given approval by the U.S. Federal Drug Administration. Treatment costs $10,000 per year per patient and does not cure the disease although it relieves some symptoms and does extend victims' lives.
1987 A three-year-old girl in the United States receives a new liver, pancreas, small intestine, and parts of the stomach and colon; this is the first successful five-organ transplant.
1987 German-born British geneticist Walter Bodmer and associates announce the discovery of a marker for a gene that causes cancer of the colon.
1988 A U.S. survey indicates that the risk of a heart attack can be halved by taking aspirin daily.
1989 Researchers in Toronto, Canada, identify a gene responsible for cystic fibrosis.
1990 A four-year-old girl in the United States has the gene for adenosine deaminase inserted into her DNA (deoxyribonucleic acid); she is the first human to receive gene therapy.
1991 Australian and British studies show that second-hand smoke is a significant cause of lung cancer. Children whose parents smoke suffer an increased risk of asthma and respiratory infections.
1992 A vaccine for hepatitis A becomes available.
1993 AIDS becomes the leading cause of death among men aged between 25 and 44 in the United States.
1993 The gene responsible for Huntington's chorea is identified. It makes it easier to test individuals for the disease and increases the chances of developing a cure.
Sept 1994 A gene that triggers breast cancer is identified and is found to be responsible for almost half the cases of inherited breast cancer and most cases of ovarian cancer.
1995 Trials begin in the United States to treat breast cancer by gene therapy. The women are injected with a virus genetically engineered to destroy their tumors.
Jan 1997 The World Health Organization (WHO) estimates that 22.6 million men, women, and children have to date been infected by HIV, the virus responsible for causing AIDS. Approximately 42% of adult sufferers are female, with the proportion of women infected steadily increasing.
May 8, 1997 U.S. AIDS researcher David D. Ho and colleagues show how aggressive treatment of HIV-1 infection with a cocktail of three antiviral drugs can drive the virus to below the limits of conventional clinical detection within eight weeks.
May 17–May 20, 1997 At a meeting of the American Society of Clinical Oncology, researchers announce the development of vaccines which cause the immune system to shrink certain cancers, such as those attacking the skin, breast, prostate, and ovaries. Unlike the normal preventative vaccines, the new vaccines fight tumors that already exist. They use components of the cancer to provoke white blood cells to attack the invader.
June 27, 1997 U.S. scientists at the National Human Genome Research Institute in Bethesda, Maryland, announce the discovery of a gene that causes Parkinson's disease.
Oct 2, 1997 U.K. scientists Moira Bruce and, independently, John Collinge and their colleagues show that the new variant form of the brain-wasting Creutzfeldt-Jakob disease (CJD) is the same disease as bovine spongiform encephalopathy (BSE or "mad cow disease") in cows.
April 22, 1998 Scientists at the Public Health Laboratory Service in London, England, report the discovery of a bacterium Pseudonas aeruginosa that is resistant to all known antibiotics. It causes a wide range of infections in people with impaired immune systems.





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  Anderson, Elizabeth Garrett (1836–1917) English physician, the first English woman to qualify in medicine. Unable to attend medical school, Anderson studied privately and was licensed by the Society of Apothecaries in London in 1865. She was physician to the Marylebone Dispensary for Women and Children (later renamed the Elizabeth Garrett Anderson Hospital), a London hospital now staffed by women and serving female patients.  
  Banting, Frederick Grant (1891–1941) Canadian physician. He discovered a technique for isolating the hormone insulin in 1921 when he and his colleague Charles Best tied off the ducts of the pancreas to determine the function of the cells known as the islets of Langerhans. This made possible the treatment of diabetes. Banting and John J. R. Macleod (1876–1935), his mentor, shared the 1923 Nobel Prize for Physiology or Medicine, and Banting divided his prize with Best. He was knighted in 1934.  
  Discovery of Insulin
  Details the discovery of the protein hormone insulin. Included here are brief descriptions of the lives of the discovery members as well as an article on the discoverer Dr F. G. Banting's death. An overview of insulin and diabetes is also included here, describing the hormone and the disease, the research experiments, and current developments.  
  Barnard, Christiaan Neethling (1922– ) South African surgeon who performed the first human heart transplant in 1967. The 54-year-old patient lived for 18 days.  
  Barnard also discovered that intestinal artresia—a congenital deformity in the form of a hole in the small intestine—is the result of an insufficient supply of blood to the fetus during pregnancy. It was a fatal defect before he developed the corrective surgery.  
  Behring, Emil von (1854–1917) German physician who discovered that the body produces antitoxins, substances able to counteract poisons released by bacteria. Using this knowledge, he developed new treatments for such diseases as diphtheria. He won the first Nobel Prize for Physiology or Medicine, 1901.  
  Behring discovered the diphtheria antitoxin and developed serum therapy together with Japanese bacteriologist Shibasaburo Kitasato, and they went on to apply the technique to tetanus. Behring also introduced early vaccination techniques against diphtheria and tuberculosis.  
  Best, Charles H(erbert) (1899–1978) Canadian physiologist. He was one of the team of Canadian scientists including Frederick Banting whose research resulted 1922 in the discovery of insulin as a treatment for diabetes. Best also discovered the vitamin choline and the enzyme histaminase, and introduced the use of the anticoagulant heparin.  
  Breuer, Josef (1842–1925) Viennese physician, one of the pioneers of psychoanalysis. He applied it successfully to cases of hysteria, and collaborated with Freud on Studien über Hysterie/Studies in Hysteria 1895.  
  Carrel, Alexis (1873–1944) U.S. surgeon born in France, whose experiments paved the way for organ transplantation. Working at the Rockefeller Institute, New York, NY, he devised a way of joining blood vessels end to end (anastomosing). This was a key move in the development of transplant surgery, as was his work on keeping organs viable outside the body, for which he was awarded the Nobel Prize for Physiology or Medicine 1912.  
  Chain, Ernst Boris (1906–1979) German-born British biochemist. After the discovery of penicillin by Alexander Fleming, Chain worked to isolate and purify it. For this work, he shared the 1945 Nobel Prize for Medicine with Fleming and Howard Florey. Chain also discovered penicillinase, an enzyme that destroys penicillin. Knighted 1969.  
  Charcot, Jean-Martin (1825–1893) French neurologist who studied hysteria, sclerosis, locomotor ataxia, and senile diseases. Among his pupils was the founder of psychiatry, Sigmund Freud. One of the most influential neurologists of his day, Charcot exhibited hysterical women at weekly public lectures, which became fashionable events. He was also fascinated by the relations between hysteria and hypnotic phenomena.  
  Cushing, Harvey Williams (1869–1939) U.S. neurologist who pioneered neurosurgery. He developed a range of techniques for the surgical treatment of brain tumors, and also studied the link between the pituitary gland and conditions such as dwarfism. He first described the chronic wasting disease now known as Cushing's syndrome.  
  Doll, (William) Richard Shaboe (1912– ) British physician who, working with Bradford Hill (1897– ), provided the first statistical proof of the link between smoking and lung cancer in 1950. In a later study of the smoking habits of doctors, they were able to show that stopping smoking immediately reduces the risk of cancer. Knighted 1971.  
  Domagk, Gerhard Johannes Paul (1895–1964) German pathologist, discoverer of antibacterial sulfonamide drugs. He found in 1932 that a coal-tar dye called Prontosil red contains chemicals with powerful antibacterial properties. Sulfanilamide became the first of the sulfonamide drugs, used—before antibiotics were discovered—to treat a wide range of conditions, including pneumonia and septic wounds. Nobel prize 1939.  
  Ehrlich, Paul (1854–1915) German bacteriologist and immunologist who produced the first cure for syphilis. He developed the arsenic compounds, in particular Salvarsan, that were used in the treatment of syphilis before the discovery of antibiotics. He shared the 1908 Nobel Prize for Physiology or Medicine with Ilya Mechnikov, awarded for his work on immunity.  
  Ehrlich also founded chemotherapy—the use of a chemical substance to destroy disease organisms in the body. He was also one of the earliest workers on immunology, and through his studies on blood samples the discipline of hematology was recognized.  
  Fleming, Alexander (1881–1955) Scottish bacteriologist who discovered the first antibiotic drug, penicillin, in 1928. In  




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  1922 he had discovered lysozyme, an antibacterial enzyme present in saliva, nasal secretions, and tears. While studying this, he found an unusual mold growing on a culture dish, which he isolated and grew into a pure culture; this led to his discovery of penicillin. It came into use in 1941. In 1945 he won the Nobel Prize for Physiology or Medicine with Howard W. Florey and Ernst B. Chain, whose research had brought widespread realization of the value of penicillin.  
  Florey, Howard Walter, Baron Florey (1898–1968) Australian pathologist whose research into lysozyme, an antibacterial enzyme discovered by Alexander Fleming, led him to study penicillin (another of Fleming's discoveries), which he and Ernst Chain isolated and prepared for widespread use. With Fleming, they were awarded the Nobel Prize for Physiology or Medicine 1945.  
  Freud, Sigmund (1856–1939) Austrian physician who pioneered the study of the unconscious mind. He developed the methods of free association and interpretation of dreams that are basic techniques of psychoanalysis. The influence of unconscious forces on people's thoughts and actions was Freud's discovery, as was his controversial theory of the repression of infantile sexuality as the root of neuroses in the adult. His influence has permeated the world to such an extent that it may be discerned today in almost every branch of thought.  
  Galen (c. 129–c. 200) Greek physician and anatomist whose ideas dominated Western medicine for almost 1,500 years. Central to his thinking were the theories of humors and the threefold circulation of the blood. He remained the highest medical authority until Andreas Vesalius and William Harvey exposed the fundamental errors of his system.  
  Galen postulated a circulation system in which the liver produced the natural spirit, the heart the vital spirit, and the brain the animal spirit. He also wrote about philosophy and believed that Nature expressed a divine purpose, a belief that became increasingly popular with the rise of Christianity (Galen himself was not a Christian). This helped to account for the enormous influence of his ideas.  
  On the Natural Faculties
  Text of this work by the Greek physician Galen.  
  Gallo, Robert Charles (1937– ) U.S. scientist credited with identifying the virus responsible for AIDS. Gallo discovered the virus, now known as human immunodeficiency virus (HIV), in 1984; the French scientist Luc Montagnier (1932– ) of the Pasteur Institute, Paris, discovered the virus, independently, in 1983. The sample in which Gallo discovered the virus was supplied by Montagnier, and it has been alleged that this may have been contaminated by specimens of the virus isolated by Montagnier a few months earlier.  
  Guérin, Camille (1872–1961) French bacteriologist who, with Albert Calmette, developed the BCG vaccine for tuberculosis 1921.  
  Hippocrates (c. 460–c. 377 B.C.) Greek physician, often called the founder of medicine. Important Hippocratic ideas include cleanliness (for patients and physicians), moderation in eating and drinking, letting nature take its course, and living where the air is good. He believed that health was the result of the "humors" of the body being in balance; imbalance caused disease. These ideas were later adopted by Galen.  
  He is known to have discovered aspirin in willow bark. The Corpus Hippocraticum/Hippocratic Collection, a group of some 70 works, is attributed to him but was probably not written by him, although the works outline his approach to medicine. They include Aphorisms and the Hippocratic Oath, which embodies the essence of medical ethics.  
  Works by Hippocrates
  Translations of the works of Hippocrates by Francis Adams in downloadable form. Seventeen works by the father of medicine are to be found here, ranging from On Ancient Medicine (this was written in 400 B.C.!) to On The Surgery. The site also includes the philosophers best known work The Oath. The text files are very large (with some exceptions, notably The Oath), but the server is fast so don't be too put off downloading.  
  Hunter, John (1728–1793) Scottish surgeon, pathologist, and comparative anatomist who insisted on rigorous scientific method. He was the first to understand the nature of digestion.  
  Jenner, Edward (1749–1823) English physician who pioneered vaccination. In Jenner's day, smallpox was a major killer. His discovery in 1796 that inoculation with cowpox gives immunity to smallpox was a great medical breakthrough.  
  Jenner observed that people who worked with cattle and contracted cowpox from them never subsequently caught smallpox. In 1798 he published his findings that a child inoculated with cowpox, then two months later with smallpox, did not get smallpox.  
  Kitasato, Shibasaburo (1852–1931) Japanese bacteriologist who discovered the plague bacillus while investigating an outbreak of plague in Hong Kong. He was the first to grow the tetanus bacillus in pure culture. He and German bacteriologist Emil von Behring discovered that increasing nonlethal doses of tetanus toxin give immunity to the disease.  
  Koch, (Heinrich Hermann) Robert (1843–1910) German bacteriologist. Koch and his assistants devised the techniques for culturing bacteria outside the body, and formulated the rules for showing whether or not a bacterium is the cause of a disease. Nobel Prize for Physiology or Medicine 1905.  
  His techniques enabled him to identify the bacteria responsible for tuberculosis (1882), cholera (1883), and other diseases. He investigated anthrax bacteria in the 1870s and showed that they form spores which spread the infection.  
  Lister, Joseph (1827–1912) 1st Baron Lister, English surgeon. He was the founder of antiseptic surgery, influenced by Louis Pasteur's work on bacteria. He introduced dressings soaked in carbolic acid and strict rules of hygiene to combat wound sepsis in hospitals. Baronet 1883, Baron 1897.  
  Nicolle, Charles Jules Henri (1866–1936) French bacteriologist whose discovery in 1909 that typhus is transmitted by  




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  the body louse made the armies of World War I introduce delousing as a compulsory part of the military routine. Nobel Prize for Physiology or Medicine 1928.  
  Pasteur, Louis (1822–1895) French chemist and microbiologist who discovered that fermentation is caused by microorganisms and developed the germ theory of disease. He also created a vaccine for rabies, which led to the foundation of the Pasteur Institute in Paris in 1888.  
Louis Pasteur
  More germs are transmitted when shaking hands than when kissing. Louis Pasteur, the pioneer of hygienic methods, refused to shake hands with acquaintances for fear of infection.  


  Ross, Ronald (1857–1932) British physician and bacteriologist, born in India. From 1881 to 1899 he served in the Indian Medical Service, and during 1895–98 identified mosquitoes of the genus Anopheles as being responsible for the spread of malaria. Nobel prize 1902.  
  Salk, Jonas Edward (1914–1995) U.S. physician and microbiologist. In 1954 he developed the original vaccine that led to virtual eradication of paralytic polio in industrialized countries. He was director of the Salk Institute for Biological Studies, University of California, San Diego, 1963–75.  
  Sydenham, Thomas (1624–1689) English physician, the first person to describe measles and to recommend the use of quinine for relieving symptoms of malaria. His original reputation as the "English Hippocrates" rested upon his belief that careful observation is more useful than speculation.  
ending of a pregnancy before the fetus is developed sufficiently to survive outside the uterus. Loss of a fetus at a later gestational age is termed premature stillbirth. Abortion may be accidental (c0016-01.gifmiscarriage) or deliberate (termination of pregnancy).
  acquired immune deficiency syndrome
full name for the disease c0016-01.gifAIDS.
in alternative medicine, a system of inserting long, thin metal needles into the body at predetermined points to relieve pain, as an anesthetic in surgery, and to assist healing. The method, developed in ancient China and increasingly popular in the West, is thought to work by stimulating the brain's own painkillers, the endorphins.
acronym for acquired immune deficiency syndrome, the gravest of the sexually transmitted diseases, or c0016-01.gifSTDs. It is caused by the human immunodeficiency virus (c0016-01.gifHIV), now known to be a c0016-01.gifretrovirus. HIV is transmitted in body fluids, mainly blood and genital secretions.
in c0016-01.gifhomoeopathy, a term used for orthodox medicine, using therapies designed to counteract the manifestations of the disease. In strict usage, allopathy is the opposite of homoeopathy.
  alternative medicine
any form of medical treatment that does not use synthetic drugs or surgery in response to the symptoms of a disease, but aims to treat the patient as a whole. The emphasis is on maintaining health (with diet and exercise) and on dealing with the underlying causes rather than just the symptoms of illness.
  Alzheimer's disease
common manifestation of c0016-01.gifdementia, thought to afflict one in 20 people over 65. Attacking the brain's "gray matter," it is a disease of mental processes rather than physical function, characterized by memory loss and progressive intellectual impairment. It was first described by Alois Alzheimer 1906. It affects up to 4 million people in the USA and around 600,000 in Britain.
sampling the amniotic fluid surrounding a fetus in the womb for diagnostic purposes. It is used to detect Down's syndrome and other genetic abnormalities. The procedure carries a 1 in 200 risk of miscarriage.
condition caused by a shortage of hemoglobin, the oxygen-carrying component of red blood cells. The main symptoms are fatigue, pallor, breathlessness, palpitations, and poor resistance to infection. Treatment depends on the cause.
agent for relieving c0016-01.gifpain. Opiates alter the perception or appreciation of pain and are effective in controlling "deep" visceral (internal) pain. Non-opiates, such as c0016-01.gifaspirin, c0016-01.gifparacetamol, and NSAIDs (nonsteroidal anti-inflammatory drugs), relieve musculoskeletal pain and reduce inflammation in soft tissues.
weakening in the wall of an artery, causing it to balloon outward with the risk of rupture and serious, often fatal, blood loss. If detected in time, some accessible aneurysms can be repaired by bypass surgery, but such major surgery carries a high risk for patients in poor health.
  angina or angina pectoris
severe pain in the chest due to impaired blood supply to the heart muscle because a coronary artery is narrowed. Faintness and difficulty in breathing accompany the pain. Treatment is by drugs or bypass surgery.
lack of desire to eat, or refusal to eat, especially the pathological condition of anorexia nervosa, most often found in adolescent girls and young women. Compulsive eating, or c0016-01.gifbulimia, distortions of body image, and depression often accompany anorexia.
disease of livestock, occasionally transmitted to humans, usually via infected hides and fleeces. It may develop as black skin pustules or severe pneumonia. Treatment is with antibiotics. Vaccination is effective.
drug that kills or inhibits the growth of bacteria and fungi. It is derived from living organisms such as fungi or bacteria, which distinguishes it from synthetic antimicrobials.
protein molecule produced in the blood by c0016-01.giflymphocytes in response to the presence of foreign or invading substances (c0016-01.gifantigens); such substances include the proteins carried on the surface of infecting microorganisms. Antibody production is only one aspect of c0016-01.gifimmunity in vertebrates.




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any substance that causes the production of c0016-01.gifantibodies by the body's immune system. Common antigens include the proteins carried on the surface of bacteria, viruses, and pollen grains. The proteins of incompatible blood groups or tissues also act as antigens, which has to be taken into account in medical procedures such as blood transfusions and organ transplants.
any substance that kills or inhibits the growth of microorganisms. The use of antiseptics was pioneered by Joseph c0016-01.gifLister.
hardening of the arteries, with thickening and loss of elasticity. It is associated with smoking, aging, and a diet high in saturated fats. The term is used loosely as a synonym for c0016-01.gifatherosclerosis.
  artificial respiration
emergency procedure to restart breathing once it has stopped; in cases of electric shock or apparent drowning, for example, the first choice is the expired-air method, the kiss of life by mouth-to-mouth breathing until natural breathing is restored.
  ascorbic acid
6H8O6 or vitamin C a relatively simple organic acid found in citrus fruits and vegetables. Lack of ascorbic acid results in scurvy.
practice of ensuring that bacteria are excluded from open sites during surgery, wound dressing, blood sampling, and other medical procedures. Aseptic technique is a first line of defense against infection.
acetylsalicylic acid, a popular pain-relieving drug (c0016-01.gifanalgesic) developed in the late 19th century as a household remedy for aches and pains. It relieves pain and reduces inflammation and fever. It is derived from the white willow tree Salix alba, and is the world's most widely used drug.
chronic condition characterized by difficulty in breathing due to spasm of the bronchi (air passages) in the lungs. Attacks may be provoked by allergy, infection, and stress. The incidence of asthma may be increasing as a result of air pollution and occupational hazard. Treatment is with bronchodilators to relax the bronchial muscles and thereby ease the breathing, and in severe cases by inhaled c0016-01.gifsteroids that reduce inflammation of the bronchi.
thickening and hardening of the walls of the arteries, associated with atheroma.
  autism, infantile
rare disorder, generally present from birth, characterized by a withdrawn state and a failure to develop normally in language or social behavior. Special education may bring about some improvement.
condition where the body's immune responses are mobilized not against ''foreign" matter, such as invading germs, but against the body itself. Diseases considered to be of autoimmune origin include myasthenia gravis, rheumatoid arthritis, and c0016-01.giflupus erythematous.
drug used in the treatment of AIDS; see c0016-01.gifzidovudine.
  bacille Calmette–Guérin
tuberculosis vaccine c0016-01.gifBCG.
  basal metabolic rate,
BMR, minimum amount of energy needed by the body to maintain life. It is measured when the subject is awake but resting, and includes the energy required to keep the heart beating, sustain breathing, repair tissues, and keep the brain and nerves functioning. Measuring the subject's consumption of oxygen gives an accurate value for BMR, because oxygen is needed to release energy from food.
abbreviation for bacille Calmette–Guérin, bacillus injectedas a vaccine to confer active immunity to c0016-01.giftuberculosis (TB).
  behavior therapy
in psychology, the application of behavioral principles, derived from learning theories, to the treatment of clinical conditions such as c0016-01.gifphobias, c0016-01.gifobsessions, and sexual and interpersonal problems.
trade name for c0016-01.gifamphetamine, a stimulant drug.
any of a class of drugs that block impulses that stimulate certain nerve endings (beta receptors) serving the heart muscle. This reduces the heart rate and the force of contraction, which in turn reduces the amount of oxygen (and therefore the blood supply) required by the heart. Beta-blockers may be useful in the treatment of angina, arrhythmia (abnormal heart rhythms), and raised blood pressure, and following heart attacks. They must be withdrawn from use gradually.
removal of a living tissue sample from the body for diagnostic examination.
  blood poisoning
presence in the bloodstream of quantities of bacteria or bacterial toxins sufficient to cause serious illness.
  blood pressure
pressure, or tension, of the blood against the inner walls of blood vessels, especially the arteries, due to the muscular pumping activity of the heart. Abnormally high blood pressure (c0016-01.gifhypertension) may be associated with various conditions or arise with no obvious cause; abnormally low blood pressure (hypotension) occurs in shock and after excessive fluid or blood loss from any cause.
  blood test
laboratory evaluation of a blood sample. There are numerous blood tests, from simple typing to establish the c0016-01.gifblood group to sophisticated biochemical assays of substances, such as hormones, present in the blood only in minute quantities.
  bovine spongiform encephalopathy, (BSE) or mad cow disease,
disease of cattle, related to c0016-01.gifscrapie in sheep, which attacks the nervous system, causing aggression, lack of coordination, and collapse. First identified in 1986, it is almost entirely confined to the U.K. By 1996 it had claimed 158,000 British cattle.
inflammation of the bronchi (air passages) of the lungs, usually caused initially by a viral infection, such as a cold or flu. It is aggravated by environmental pollutants, especially smoking, and results in a persistent cough, irritated mucus-secreting glands, and large amounts of sputum.
eating disorder in which large amounts of food are consumed in a short time ("binge"), usually followed by depression and self-criticism. The term is often used for bulimia nervosa, an emotional disorder in which eating is followed by deliberate vomiting and purging. This may be a chronic stage in c0016-01.gifanorexia nervosa.




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  Cesarean section
surgical operation to deliver a baby by way of an incision in the mother's abdominal and uterine walls. It may be recommended for almost any obstetric complication implying a threat to mother or baby.
group of diseases characterized by abnormal proliferation of cells. Cancer (malignant) cells are usually degenerate, capable only of reproducing themselves (tumor formation). Malignant cells tend to spread from their site of origin by traveling through the bloodstream or lymphatic system. Cancer kills about 6 million people a year worldwide.
chemical compound composed of carbon, hydrogen, and oxygen, with the basic formula C
m(H2O)n, and related compounds with the same basic structure but modified functional groups. As sugar and starch, carbohydrates are an important part of a balanced human diet, providing energy for life processes including growth and movement. Excess carbohydrate intake can be converted into fat and stored in the body.
any agent that increases the chance of a cell becoming cancerous (see c0016-01.gifcancer), including various chemical compounds, some viruses, X-rays, and other forms of ionizing radiation. The term is often used more narrowly to mean chemical carcinogens only.
malignant c0016-01.giftumor arising from the skin, the glandular tissues, or the mucous membranes that line the gut and lungs.
anyone who harbors an infectious organism without ill effects but can pass the infection to others. The term is also applied to those who carry a recessive gene for a disease or defect without manifesting the condition.
main protein of milk used as a protein supplement in the treatment of malnutrition.
any medical treatment with chemicals. It usually refers to treatment of cancer with cytotoxic and other drugs.
  chickenpox or varicella
common, usually mild disease, caused by a virus of the c0016-01.gifherpes group and transmitted by airborne droplets. Chickenpox chiefly attacks children under the age of ten. The incubation period is two to three weeks. One attack normally gives immunity for life.
in alternative medicine, technique of manipulation of the spine and other parts of the body, based on the principle that physical disorders are attributable to aberrations in the functioning of the nervous system, which manipulation can correct.
viruslike bacteria which live parasitically in animal cells, and cause disease in humans and birds. Chlamydiae are thought to be descendants of bacteria that have lost certain metabolic processes. In humans, a strain of chlamydia causes c0016-01.giftrachoma, a disease found mainly in the tropics (a leading cause of blindness); venereally transmitted chlamydiae cause genital and urinary infections.
disease caused by infection with various strains of the bacillus Vibrio cholerae, transmitted in contaminated water and characterized by violent diarrhea and vomiting. It is prevalent in many tropical areas.
white, crystalline sterol found throughout the body, especially in fats, blood, nerve tissue, and bile; it is also provided in the diet by foods such as eggs, meat, and butter. A high level of cholesterol in the blood is thought to contribute to atherosclerosis (hardening of the arteries).
term used to describe a condition that is of slow onset and then runs a prolonged course, such as rheumatoid arthritis or chronic bronchitis. In contrast, an acute condition develops quickly and may be of relatively short duration.
  clinical psychology
branch of psychology dealing with the understanding and treatment of health problems, particularly mental disorders. The main problems dealt with include anxiety, phobias, depression, obsessions, sexual and marital problems, drug and alcohol dependence, childhood behavioral problems, psychoses (such as schizophrenia), mental disability, and brain disease (such as dementia) and damage. Other areas of work include forensic psychology (concerned with criminal behavior) and health psychology.
  cold, common
minor disease of the upper respiratory tract, caused by a variety of viruses. Symptoms are headache, chill, nasal discharge, sore throat, and occasionally cough. Research indicates that the virulence of a cold depends on psychological factors and either a reduction or an increase of social or work activity, as a result of stress, in the previous six months.
inflammation of the colon (large intestine) with diarrhea (often bloody). It is usually due to infection or some types of bacterial dysentery.
  complementary medicine
systems of care based on methods of treatment or theories of disease that differ from those taught in most western medical schools. See c0016-01.gifalternative medicine.
  congenital disease
disease present at birth. It is not necessarily genetic in origin; for example, congenital herpes may be acquired by the baby as it passes through the mother's birth canal.
any of several steroid hormones secreted by the cortex of the adrenal glands; also synthetic forms with similar properties. Corticosteroids have anti-inflammatory and immunosuppressive effects and may be used to treat a number of conditions, including rheumatoid arthritis, severe allergies, asthma, some skin diseases, and some cancers. Side effects can be serious, and therapy must be withdrawn very gradually.
  Creutzfeldt–Jakob disease (CJD)
rare brain disease that causes progressive physical and mental deterioration, leading to death usually within a year of onset. It claims one person in every million and is universally fatal. It has been linked with c0016-01.gifbovine spongiform encephalopathy (BSE), and there have also been occurrences in people treated with pituitary hormones derived from cows for growth or fertility problems. Research published by British pathologists in 1997 proved that the new variant of CJD (vCJD) is caused by the same agent that causes BSE, indicating that the disease has jumped species, from cattle to humans.




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  crib death or sudden infant death syndrome (SIDS)
death of an apparently healthy baby, almost always during sleep. It is most common in the winter months, and strikes more boys than girls. The cause is not known but risk factors that have been identified include prematurity, respiratory infection, overheating, and sleeping position.
inflammation of the larynx in small children, with harsh, difficult breathing and hoarse coughing. Croup is most often associated with viral infection of the respiratory tract.
chemical name for vitamin B
12, which is normally produced by microorganisms in the gut. The richest sources are liver, fish, and eggs. It is essential to the replacement of cells, the maintenance of the myelin sheath, which insulates nerve fibers, and the efficient use of folic acid, another vitamin in the B complex. Deficiency can result in pernicious anemia (defective production of red blood cells), and possible degeneration of the nervous system.
mental deterioration as a result of physical changes in the brain. It may be due to degenerative change, circulatory disease, infection, injury, or chronic poisoning. Senile dementia, a progressive loss of mental faculties such as memory and orientation, is typically a disease process of old age, and can be accompanied by c0016-01.gifdepression.
emotional state characterized by sadness, unhappy thoughts, apathy, and dejection. Sadness is a normal response to major losses such as bereavement or unemployment. After childbirth, postnatal depression is common. However, clinical depression, which is prolonged or unduly severe, often requires treatment, such as antidepressant medication, cognitive therapy, or, in very rare cases, electroconvulsive therapy (ECT), in which an electrical current is passed through the brain.
  developmental psychology
study of development of cognition and behavior from birth to adulthood.
disease diabetes mellitus in which a disorder of the islets of Langerhans in the c0016-01.gifpancreas prevents the body producing the hormone c0016-01.gifinsulin, so that sugars cannot be used properly. Treatment is by strict dietary control and oral or injected insulin, depending on the type of diabetes.
frequent or excessive action of the bowels so that the feces are liquid or semiliquid. It is caused by intestinal irritants (including some drugs and poisons), infection with harmful organisms (as in dysentery, salmonella, or cholera), or allergies.
acute infectious disease in which a membrane forms in the throat (threatening death by asphyxia), along with the production of a powerful toxin that damages the heart and nerves. The organism responsible is a bacterium (Corynebacterium diphtheriae). It is treated with antitoxin and antibiotics.
any of a range of substances, natural or synthetic, administered to humans and animals as therapeutic agents: to diagnose, prevent, or treat disease, or to assist recovery from injury. Traditionally many drugs were obtained from plants or animals; some minerals also had medicinal value. Today, increasing numbers of drugs are synthesized in the laboratory.
  drug misuse
illegal use of drugs for nontherapeutic purposes. Drugs used illegally include: narcotics, such as heroin, morphine, and the synthetic opioids; barbiturates; amphetamines and related substances; benzodiazepine tranquilizers; cocaine, LSD, and cannabis.
infection of the large intestine causing abdominal cramps and painful c0016-01.gifdiarrhea with blood. There are two kinds of dysentery: amebic (caused by a protozoan), common in the tropics, which may lead to liver damage; and bacterial, the kind most often seen in the temperate zones.
  evening primrose oil
plant oil rich in gamma-linoleic acid (GLA). The body converts GLA into substances which resemble hormones, and evening primrose oil is beneficial in relieving the symptoms of premenstrual tension. It is also used in treating eczema and chronic fatigue syndrome.
  food poisoning
any acute illness characterized by vomiting and diarrhea and caused by eating food contaminated with harmful bacteria (for example, listeriosis), poisonous food (for example, certain mushrooms, puffer fish), or poisoned food (such as lead or arsenic introduced accidentally during processing). A frequent cause of food poisoning is c0016-01.gifSalmonella bacteria. Salmonella comes in many forms, and strains are found in cattle, pigs, poultry, and eggs.
death and decay of body tissue (often of a limb) due to bacterial action; the affected part gradually turns black and causes blood poisoning.
inflammation of the stomach and intestines, giving rise to abdominal pain, vomiting, and diarrhea. It may be caused by food or other poisoning, allergy, or infection. Dehydration may be severe and it is a particular risk in infants.
  gene therapy
medical technique for curing or alleviating inherited diseases or defects; certain infections, and several kinds of cancer in which affected cells from a sufferer would be removed from the body, the c0016-01.gifDNA repaired in the laboratory (genetic engineering), and the functioning cells reintroduced. In 1990 a genetically engineered gene was used for the first time to treat a patient.
  German measles or rubella
mild, communicable virus disease, usually caught by children. It is marked by a sore throat, pinkish rash, and slight fever, and has an incubation period of two to three weeks. If a woman contracts it in the first three months of pregnancy, it may cause serious damage to the unborn child.
plant with a thick forked aromatic root used in alternative medicine as a tonic.
  glandular fever or infectious mononucleosis
viral disease characterized at onset by fever and painfully swollen lymph nodes; there may also be digestive upset, sore throat, and skin rashes. Lassitude persists for months and even years, and recovery can be slow. It is caused by the Epstein–Barr virus.
  glue-sniffing or solvent misuse
inhalation of the fumes from organic solvents of the type found in paints, lighter fuel, and glue, for their hallucinatory effects. As well as being addictive, solvents are dangerous for their effects on the user's liver, heart, and lungs.




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enlargement of the thyroid gland seen as a swelling on the neck. It is most pronounced in simple goiter, which is caused by iodine deficiency. More common is toxic goiter or hyperthyroidism, caused by overactivity of the thyroid gland.
common sexually transmitted disease arising from infection with the bacterium Neisseria gonorrhoeae, which causes inflammation of the genito-urinary tract. After an incubation period of two to ten days, infected men experience pain while urinating and a discharge from the penis; infected women often have no external symptoms.
medical specialty concerned with disorders of the female reproductive system.
medical specialty concerned with disorders of the blood.
  health, world
the health of people worldwide is monitored by the World Health Organization (WHO). Outside the industrialized world in particular, poverty and degraded environmental conditions mean that easily preventable diseases are widespread: WHO estimated in 1990 that 1 billion people, or 20% of the world's population, were diseased, in poor health, or malnourished. In North Africa and the Middle East, 25% of the population were ill.
  heart attack or myocardial infarction
sudden onset of gripping central chest pain, often accompanied by sweating and vomiting, caused by death of a portion of the heart muscle following obstruction of a coronary artery by thrombosis (formation of a blood clot). Half of all heart attacks result in death within the first two hours, but in the remainder survival has improved following the widespread use of thrombolytic (clot-buster) drugs.
any inflammatory disease of the liver, usually caused by a virus. Other causes include alcohol, drugs, gallstones, lupus erythematous, and amoebic dysentery. Symptoms include weakness, nausea, and jaundice.
prescription and use of plants and their derivatives for medication.
any of several infectious diseases caused by viruses of the herpes group. Herpes simplex I is the causative agent of a common inflammation, the cold sore. Herpes simplex II is responsible for genital herpes, a highly contagious, sexually transmitted disease characterized by painful blisters in the genital area. It can be transmitted in the birth canal from mother to newborn. Herpes zoster causes shingles; another herpes virus causes chickenpox.
abbreviation for human immunodeficiency virus, the infectious agent that is believed to cause c0016-01.gifAIDS.
  holistic medicine
umbrella term for an approach that virtually all alternative therapies profess, which considers the overall health and lifestyle profile of a patient, and treats specific ailments not primarily as conditions to be alleviated but rather as symptoms of more fundamental disease.
  homoeopathy or homoeopathy
system of alternative medicine based on the principle that symptoms of disease are part of the body's self-healing processes, and on the practice of administering extremely diluted doses of natural substances found to produce in a healthy person the symptoms manifest in the illness being treated.
abnormally high c0016-01.gifblood pressure due to a variety of causes, leading to excessive contraction of the smooth muscle cells of the walls of the arteries. It increases the risk of kidney disease, stroke, and heart attack.
surgical removal of all or part of the uterus (womb). The operation is performed to treat fibroids (benign tumors growing in the uterus) or cancer; also to relieve heavy menstrual bleeding. A woman who has had a hysterectomy will no longer menstruate and cannot bear children.
protection that organisms have against foreign microorganisms, such as bacteria and viruses, and against cancerous cells (see c0016-01.gifcancer). The cells that provide this protection are called white blood cells, or leukocytes, and make up the immune system. They include neutrophils and macrophages, which can engulf invading organisms and other unwanted material, and natural killer cells that destroy cells infected by viruses and cancerous cells. Some of the most important immune cells are the B cells and T cells. Immune cells coordinate their activities by means of chemical messengers or lymphokines, including the antiviral messenger interferon. The lymph nodes play a major role in organizing the immune response.
conferring immunity to infectious disease by artificial methods. The most widely used technique is c0016-01.gifvaccination.
invasion of the body by disease-causing organisms (pathogens, or germs) that become established, multiply, and produce symptoms. Bacteria and viruses cause most diseases, but diseases are also caused by other microorganisms, protozoans, and other parasites.
any of various viral infections primarily affecting the air passages, accompanied by systemic effects such as fever, chills, headache, joint and muscle pains, and lassitude. Treatment is with bed rest and analgesic drugs such as aspirin.
injection into the body of dead or weakened disease-carrying organisms or their toxins (c0016-01.gifvaccine) to produce immunity by inducing a mild form of a disease.
protein hormone, produced by specialized cells in the islets of Langerhans in the pancreas, that regulates the metabolism (rate of activity) of glucose, fats, and proteins. It is used in treating c0016-01.gifdiabetes.
severe protein deficiency in children under five years, resulting in retarded growth, lethargy, edema, diarrhea, and a swollen abdomen. It is common in Third World countries with a high incidence of malnutrition.
secretion of milk in mammals, from the mammary glands. In late pregnancy, the cells lining the lobules inside the mammary glands begin extracting substances from the blood to produce milk. The supply of milk starts shortly after birth with the production of colostrum, a clear fluid consisting largely of water, protein, antibodies, and vitamins. The




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  production of milk continues practically as long as the baby continues to suckle.  
  Lassa fever
acute disease caused by an arenavirus, first detected 1969, and spread by a species of rat found only in West Africa. It is classified as a hemorrhagic fever and characterized by high fever, headache, muscle pain, and internal bleeding. There is no known cure, the survival rate being less than 50%.
  leprosy or Hansen's disease
chronic, progressive disease caused by a bacterium Mycobacterium leprae closely related to that of tuberculosis. The infection attacks the skin and nerves. It is controlled with drugs. In 1998 there were an estimated 1.5 million cases of leprosy, with 60% of these being in India.
any one of a group of cancers of the blood cells, with widespread involvement of the bone marrow and other blood-forming tissue. The central feature of leukemia is run-away production of white blood cells that are immature or in some way abnormal. These rogue cells, which lack the defensive capacity of healthy white cells, overwhelm the normal ones, leaving the victim vulnerable to infection. Treatment is with radiotherapy and cytotoxic drugs to suppress replication of abnormal cells, or by bone-marrow transplant.
soft, ductile, silver-white, metallic element used in medicine to treat manic depression.
parasitic insect that lives on mammals. It has a flat, segmented body without wings, and a tube attached to the head, used for sucking blood from its host.
  lung cancer
cancer of the lung. The main risk factor is smoking, with almost nine out of ten cases attributed to it. Other risk factors include workspace exposure to carcinogenic substances such as asbestos, and radiation. Warning symptoms include a persistent and otherwise unexplained cough, breathing difficulties, and pain in the chest or shoulder. Treatment is with chemotherapy, radiotherapy, and surgery.
any of various diseases characterized by lesions of the skin. One form (lupus vulgaris) is caused by the tubercle bacillus (see tuberculosis). The organism produces ulcers that spread and eat away the underlying tissues. Treatment is primarily with standard antituberculous drugs, but ultraviolet light may also be used.
infectious parasitic disease of the tropics transmitted by mosquitoes, marked by periodic fever and an enlarged spleen. Malaria affects about 267 million people in 103 countries, and in 1995 around 2.1 million people died of the disease.
condition resulting from a defective diet where certain important food nutrients (such as protein, vitamins, or carbohydrates) are absent. It can lead to deficiency diseases.
  manic depression or bipolar disorder
mental disorder characterized by recurring periods of either c0016-01.gifdepression or mania (inappropriate elation, agitation, and rapid thought and speech) or both.
abbreviation for myalgic encephalomyelitis, a popular name for chronic fatigue syndrome.
acute virus disease (rubeola), spread by airborne infection. Symptoms are fever, severe catarrh, small spots inside the mouth, and a raised, blotchy red rash appearing for about a week after two weeks' incubation. Prevention is by vaccination.
highly malignant tumor of the melanin-forming cells (melanocytes) of the skin. It develops from an existing mole in up to two thirds of cases, but can also arise in the eye or mucous membranes. Malignant melanoma is the most dangerous of the skin cancers; it is associated with brief but excessive exposure to sunlight. It is easily treated if caught early but deadly once it has spread. There is a genetic factor in some cases.
inflammation of the meninges (membranes) surrounding the brain, caused by bacterial or viral infection. Bacterial meningitis, though treatable by antibiotics, is the more serious threat. Diagnosis is by lumbar puncture.
  mental illness
disordered functioning of the mind. It is broadly divided into two categories: c0016-01.gifneurosis, in which the patient remains in touch with reality; and c0016-01.gifpsychosis, in which perception, thought, and belief are disordered.
spontaneous expulsion of a fetus from the womb before it is capable of independent survival. Often, miscarriages are due to an abnormality in the developing fetus.
narcotic alkaloid C
17H19NO3 derived from opium and prescribed only to alleviate severe pain. Its use produces serious side effects, including nausea, constipation, tolerance, and addiction, but it is highly valued for the relief of the terminally ill.
  mumps or infectious parotitis
virus infection marked by fever, pain, and swelling of one or both parotid salivary glands (situated in front of the ears). It is usually shortlived in children, although meningitis is a possible complication. In adults the symptoms are more serious and it may cause sterility in men.
pain-relieving and sleep-inducing drug. The term is usually applied to heroin, morphine, and other opium derivatives, but may also be used for other drugs which depress brain activity, including anesthetic agents and hypnotics.
any lump or tumor, which may be benign or malignant (cancerous).
in psychology, a general term referring to emotional disorders, such as anxiety, depression, and phobias. The main disturbance tends to be one of mood; contact with reality is relatively unaffected, in contrast to c0016-01.gifpsychosis.
condition of being overweight (generally, 20% or more above the desirable weight for one's sex, build, and height). Obesity increases susceptibility to disease, strains the vital organs, and reduces life expectancy; it is usually remedied by controlled weight loss, healthy diet, and exercise.
medical specialty concerned with the management of pregnancy, childbirth, and the immediate postnatal period.
medical speciality concerned with the diagnosis and treatment of c0016-01.gifneoplasms, especially cancer.




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system of alternative medical practice that relies on physical manipulation to treat mechanical stress.
mental disorder marked by delusions of grandeur or persecution. In popular usage, paranoia means baseless or exaggerated fear and suspicion.
organism that lives on or in another organism (called the host) and depends on it for nutrition, often at the expense of the host's welfare. Parasites that live inside the host, such as liver flukes and tapeworms, are called endoparasites; those that live on the exterior, such as fleas and lice, are called ectoparasites.
any microorganism that causes disease. Most pathogens are c0016-01.gifparasites, and the diseases they cause are incidental to their search for food or shelter inside the host. Nonparasitic organisms, such as soil bacteria or those living in the human gut and feeding on waste foodstuffs, can also become pathogenic to a person whose immune system or liver is damaged.
medical specialty concerned with the study of disease processes and how these provoke structural and functional changes in the body.
medical specialty concerned with the care of children.
any of a group of c0016-01.gifantibiotic (bacteria killing) compounds obtained from filtrates of molds of the genus Penicillium (especially P. notatum) or produced synthetically. Penicillin was the first antibiotic to be discovered (by Alexander Fleming); it kills a broad spectrum of bacteria, many of which cause disease in humans.
excessive irrational fear of an object or situation—for example, agoraphobia (fear of open spaces and crowded places), acrophobia (fear of heights), and claustrophobia (fear of enclosed places).
one form of vitamin K, a fat-soluble chemical found in green vegetables. It is involved in the production of prothrombin, which is essential in blood clotting.
organ that attaches the developing embryo or fetus to the uterus in placental mammals (mammals other than marsupials, platypuses, and echidnas). Composed of maternal and embryonic tissue, it links the blood supply of the embryo to the blood supply of the mother, allowing the exchange of oxygen, nutrients, and waste products. The two blood systems are not in direct contact, but are separated by thin membranes, with materials diffusing across from one system to the other. The placenta also produces hormones that maintain and regulate pregnancy. It is shed as part of the afterbirth.
inflammation of the lungs, generally due to bacterial or viral infection but also to particulate matter or gases. It is characterized by a build-up of fluid in the alveoli, the clustered air sacs (at the ends of the air passages) where oxygen exchange takes place.
  polio, poliomyelitis
viral infection of the central nervous system affecting nerves that activate muscles. Two kinds of vaccine are available, one injected and one given by mouth. In 1997 the World Health Organization reported that causes of polio had dropped by nearly 90% since 1988. Most cases remain in Africa and southeast Asia (in 1998 India accounted for over 30% of the world's polio cases).
any measure taken to prevent disease, including exercise and c0016-01.gifvaccination. Prophylactic (preventive) medicine is an aspect of public-health provision that is receiving increasing attention.
branch of medicine dealing with the diagnosis and treatment of mental disorder, normally divided into the areas of neurotic conditions, including anxiety, depression, and hysteria, and psychotic disorders, such as schizophrenia. Psychiatric treatment consists of drugs, analysis, or electroconvulsive therapy (ECT).
theory and treatment method for neuroses, developed by Sigmund Freud in the 1890s. Psychoanalysis asserts that the impact of early childhood sexuality and experiences, stored in the c0016-01.gifunconscious, can lead to the development of adult emotional problems. The main treatment method involves the free association of ideas, and their interpretation by patient and analyst, in order to discover these long-buried events and to grasp their significance to the patient, linking aspects of the patient's historical past with the present relationship to the analyst.
  psychosis or psychotic disorder
general term for a serious mental disorder where the individual commonly loses contact with reality and may experience hallucinations or delusions (fixed false beliefs). For example, in a paranoid psychosis, an individual may believe that others are plotting against him or her. A major type of psychosis is schizophrenia.
physical symptom or disease thought to arise from emotional or mental factors.
any treatment for psychological problems that involves talking rather than surgery or drugs. Examples include cognitive therapy and psychoanalysis.
yellowish fluid that forms in the body as a result of bacterial infection; it includes white blood cells (leukocytes), living and dead bacteria, dead tissue, and serum. An enclosed collection of pus is called an abscess.
antimalarial drug extracted from the bark of the cinchona tree. It is a bitter alkaloid, with the formula C
  rabies or hydrophobia
viral disease of the central nervous system that can afflict all warm-blooded creatures. It is caused by a lyssavirus. It is almost invariably fatal once symptoms have developed. Its transmission to humans is generally by a bite from an infected animal. Rabies continues to kill hundreds of thousands of people every year; almost all these deaths occur in Asia, Africa, and South America.
treatment of disease by radiation from X-ray machines or radioactive sources. Radiation, which reduces the activity of dividing cells, is of special value for its effect on malignant tissues, certain nonmalignant tumors, and some diseases of the skin.
  retinol or vitamin A
fat-soluble chemical derived from ß-carotene and found in milk, butter, cheese, egg yolk, and liver.




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  Lack of retinol in the diet leads to the eye disease xerophthalmia.  
any of a family of viruses (Retroviridae) containing the genetic material RNA rather than the more usual DNA.
  rheumatic fever or acute rheumatism
acute or chronic illness characterized by fever and painful swelling of joints. Some victims also experience involuntary movements of the limbs and head, a form of chorea. It is now rare in the developed world.
  riboflavin or vitamin B2
vitamin of the B complex important in cell respiration. It is obtained from eggs, liver, and milk. A deficiency in the diet causes stunted growth.
defective growth of bone in children due to an insufficiency of calcium deposits. The bones, which do not harden adequately, are bent out of shape. It is usually caused by a lack of vitamin D and insufficient exposure to sunlight. Renal rickets, also a condition of malformed bone, is associated with kidney disease.
any of various contagious skin infections due to related kinds of fungus, usually resulting in circular, itchy, discolored patches covered with scales or blisters. The scalp and feet (athlete's foot) are generally involved. Treatment is with antifungal preparations.
technical term for German measles.
any of a very varied group of bacteria, genus Salmonella that colonize the intestines of humans and some animals. Some strains cause typhoid and paratyphoid fevers, while others cause salmonella food poisoning, which is characterized by stomach pains, vomiting, diarrhea, and headache. It can be fatal in elderly people, but others usually recover in a few days without antibiotics. Most cases are caused by contaminated animal products, especially poultry meat.
malignant tumor arising from the fat, muscles, bones, cartilage, or blood and lymph vessels and connective tissues. Sarcomas are much less common than carcinomas.
contagious infection of the skin caused by the parasitic itch mite Sarcoptes scabiei, which burrows under the skin to deposit eggs. Treatment is by antiparasitic creams and lotions.
  scarlet fever or scarlatina
acute infectious disease, especially of children, caused by the bacteria in the Streptococcus pyogenes group. It is marked by fever, vomiting, sore throat, and a bright red rash spreading from the upper to the lower part of the body. The rash is followed by the skin peeling in flakes. It is treated with antibiotics.
mental disorder, a psychosis of unknown origin, which can lead to profound changes in personality, behavior, and perception, including delusions and hallucinations. It is more common in males and the early-onset form is more severe than when the illness develops in later life. Modern treatment approaches include drugs, family therapy, stress reduction, and rehabilitation.
disease caused by deficiency of vitamin C (ascorbic acid), which is contained in fresh vegetables and fruit. The signs are weakness and aching joints and muscles, progressing to bleeding of the gums and other spontaneous hemorrhage, and drying-up of the skin and hair.
general term for infectious change in the body caused by bacteria or their toxins.
general term for any form of c0016-01.gifblood poisoning.
clear fluid that separates out from clotted blood. It is blood plasma with the anticoagulant proteins removed, and contains c0016-01.gifantibodies and other proteins, as well as the fats and sugars of the blood. It can be produced synthetically, and is used to protect against disease.
  sexually transmitted disease (STD)
any disease transmitted by sexual contact. STDs include venereal disease, c0016-01.gifAIDS, scabies, and viral c0016-01.gifhepatitis. The WHO estimate that there are 356,000 new cases of STDs daily worldwide (1995).
common name for c0016-01.gifherpes zoster, a disease characterized by infection of sensory nerves, with pain and eruption of blisters along the course of the affected nerves.
  sleeping sickness
infectious disease of tropical Africa, a form of c0016-01.giftrypanosomiasis. Early symptoms include fever, headache, and chills, followed by anemia and joint pains. Later, the disease attacks the central nervous system, causing drowsiness, lethargy, and, if left untreated, death. Sleeping sickness is caused by either of two trypanosomes, Trypanosoma gambiense or T. rhodesiense. Control is by eradication of the tsetse fly, which transmits the disease to humans.
acute, highly contagious viral disease, marked by aches, fever, vomiting, and skin eruptions leaving pitted scars. Widespread vaccination programs have eradicated this often fatal disease.
abbreviation for c0016-01.gifsexually transmitted disease.
  stroke or cerebrovascular accident or apoplexy
interruption of the blood supply to part of the brain due to sudden bleeding in the brain (cerebral hemorrhage) or embolism or thrombosis. Strokes vary in severity from producing almost no symptoms to proving rapidly fatal. In between are those (often recurring) that leave a wide range of impaired function, depending on the size and location of the event.
any of a group of compounds containing the chemical group sulfonamide (SO
2NH2) or its derivatives, which were, and still are in some cases, used to treat bacterial diseases.
popular name given to an infectious bacterium that has developed resistance to most or all known antibiotics.
branch of medicine concerned with the treatment of disease, abnormality, or injury by operation. Traditionally it has been performed by means of cutting instruments, but today a number of technologies are used to treat or remove lesions, including ultrasonic waves and laser surgery.
sexually transmitted disease caused by the spiral-shaped bacterium (spirochete) Treponema pallidum. Untreated, it runs its course in three stages over many years, often starting with a painless hard sore, or chancre, developing within a




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  month on the area of infection (usually the genitals). The second stage, months later, is a rash with arthritis, hepatitis, and/or meningitis. The third stage, years later, leads eventually to paralysis, blindness, insanity, and death. The Wassermann test is a diagnostic blood test for syphilis.  
any of various parasitic flatworms of the class Cestoda. They lack digestive and sense organs, can reach 15 m/50 ft in length, and attach themselves to the host's intestines by means of hooks and suckers. The larvae of tapeworms usually reach humans in imperfectly cooked meat or fish, causing anemia and intestinal disorders.
abbreviation for the infectious disease c0016-01.giftuberculosis.
  tetanus or lockjaw
acute disease caused by the toxin of the bacillus Clostridium tetani, which usually enters the body through a wound. The bacterium is chiefly found in richly manured soil. Untreated, in seven to ten days tetanus produces muscular spasm and rigidity of the jaw spreading to other parts of the body, convulsions, and death. There is a vaccine, and the disease may be treatable with tetanus antitoxin and antibiotics.
one of a group of antibiotic compounds having in common the four-ring structure of chlortetracycline, the first member of the group to be isolated. They are prepared synthetically or obtained from certain bacteria of the genus Streptomyces. They are broad-spectrum antibiotics, effective against a wide range of disease-causing bacteria.
  thiamine or vitamin B1
a water-soluble vitamin of the B complex. It is found in seeds and grain. Its absence from the diet causes the disease beriberi.
condition in which a blood clot forms in a vein or artery, causing loss of circulation to the area served by the vessel. If it breaks away, it often travels to the lungs, causing pulmonary embolism.
organ in vertebrates, situated in the upper chest cavity in humans. The thymus processes lymphocyte cells to produce T-lymphocytes (T denotes "thymus-derived"), which are responsible for binding to specific invading organisms and killing them or rendering them harmless.
another term for c0016-01.gifblood poisoning; toxemia of pregnancy is another term for pre-eclampsia.
any of several debilitating long-term diseases caused by a trypanosome (protozoan of the genus Trypanosoma). They include sleeping sickness in Africa, transmitted by the bites of tsetse flies, and Chagas's disease in Central and South America, spread by assassin bugs.
(TB) formerly known as consumption or phthisis, infectious disease caused by the bacillus Mycobacterium tuberculosis. It takes several forms, of which pulmonary tuberculosis is by far the most common. A vaccine, BCG, was developed around 1920 and the first antituberculosis drug, streptomycin, in 1944. The bacterium is mostly kept in check by the body's immune system; about 5% of those infected develop the disease. Treatment of patients with a combination of anti-TB medicines for 6–8 months produces a cure rate of 80%. There are 7 million new cases of TB annually worldwide (1998) and 3 million deaths.
overproduction of cells in a specific area of the body, often leading to a swelling or lump. Tumors are classified as benign or malignant. Benign tumors grow more slowly, do not invade surrounding tissues, do not spread to other parts of the body, and do not usually recur after removal. However, benign tumors can be dangerous in areas such as the brain. The most familiar types of benign tumor are warts on the skin. In some cases, there is no sharp dividing line between benign and malignant tumors.
  typhoid fever
acute infectious disease of the digestive tract, caused by the bacterium Salmonella typhi, and usually contracted through a contaminated water supply. It is characterized by bowel hemorrhage and damage to the spleen. Treatment is with antibiotics.
any one of a group of infectious diseases caused by bacteria transmitted by lice, fleas, mites, and ticks. Symptoms include fever, headache, and rash. The most serious form is epidemic typhus, which also affects the brain, heart, lungs, and kidneys and is associated with insanitary overcrowded conditions. Treatment is by antibiotics.
any preparation of modified pathogens (viruses or bacteria) that is introduced into the body, usually either orally or by a hypodermic syringe, to induce the specific antibody reaction that produces c0016-01.gifimmunity against a particular disease.
  valvular heart disease
damage to the heart valves, leading to either narrowing of the valve orifice when it is open (stenosis) or leaking through the valve when it is closed (regurgitation).
infectious particle consisting of a core of nucleic acid (DNA or RNA) enclosed in a protein shell. Viruses are acellular and able to function and reproduce only if they can invade a living cell to use the cell's system to replicate themselves. In the process they may disrupt or alter the host cell's own DNA. The healthy human body reacts by producing an antiviral protein, c0016-01.gifinterferon, which prevents the infection spreading to adjacent cells.
any of various chemically unrelated organic compounds that are necessary in small quantities for the normal functioning of the human body. Vitamins must be supplied by the diet because the body cannot make them. They are normally present in adequate amounts in a balanced diet. Deficiency of a vitamin may lead to a metabolic disorder ("deficiency disease"), which can be remedied by sufficient intake of the vitamin. They are generally classified as water-soluble (B and C) or fat-soluble (A, D, E, and K).
acronym for World Health Organization.
  whooping cough or pertussis
acute infectious disease, seen mainly in children, caused by colonization of the air passages by the bacterium Bordetella pertussis. There may be catarrh, mild fever, and loss of appetite, but the main symptom is violent coughing, associated with the sharp intake of breath that is the characteristic "whoop," and often followed by vomiting and severe nose bleeds. The cough may persist for weeks.
  yellow fever
or yellow jack acute tropical viral disease, prevalent in the Caribbean area, Brazil, and on the west coast of Africa. The yellow fever virus is an arbovirus transmitted by mosquitoes. Its symptoms include a high fever, headache, joint




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  and muscle pains, vomiting, and yellowish skin (jaundice, possibly leading to liver failure); the heart and kidneys may also be affected. The mortality rate is 25%, with 91% of all cases occurring in Africa.  
formerly AZT, antiviral drug used in the treatment of c0016-01.gifAIDS. It is not a cure for AIDS but is effective in prolonging life; it does not, however, delay the onset of AIDS in people carrying the virus.
  Further Reading  
  Ackerknecht, Erwin H. A Short History of Medicine (1968)  
  Altman, Lawrence K. Who Goes First: The Story of Self-Experimentation in Medicine (1988)  
  American Medical Association International Classification of Diseases: Clinical Modification (1998)  
  Asher, Richard Talking Sense (1972)  
  Blaue, David, Brunner, Eric, and Wilkinson, Richard G. Health and Social Organization: Towards a Health Policy in the Twenty-First Century (1996)  
  Bliss, Michael The Discovery of Insulin (1982)  
  Briant, Keith Passionate Paradox (1962)  
  Bynum, W. F. and Porter, Roy Companion Encyclopedia of the History of Medicine (1993)  
  Chalmers, Irena Foods that Harm, Foods that Heal (1996)  
  Clare, Anthony W Psychiatry in Dissent (1980)  
  Conrad, Lawrence; Neve, Michael; Nuttonand, Vivian; and Porter, Roy The Western Medical Tradition: 800 B.C. to A.D. 1800 (1995)  
  Dally, P. and Gomez, J. Anorexia Nervosa (1979)  
  Daniel, Thomas and Robbins, Frederick (eds.) Polio (1998)  
  Desowitz, Robert Tropical Diseases: from 50,000 B.C. to 2500 A.D. (1998)  
  Dubos, René Louis Pasteur: Free Lance of Science (1986)  
  Duncan, R. and Weston-Smith, M. The Encyclopaedia of Medical Ignorance (1984)  
  Dworkins, Ronald Life's Dominion: An Argument about Abortion and Euthanasia (1993)  
  Eastwood, Martin Anthony Principles of Human Nutrition (1997)  
  Ellenberger, Henri F. The Discovery of the Unconscious (1970)  
  Fabrega, Horacio Evolution of Sickness and Healing (1997)  
  Fisher, Richard Joseph Lister, 1827–1912 (1977)  
  Fosbery, Richard Human Health and Disease (1997)  
  Ganellin, C. R. and Roberts, S. M. Medicinal Chemistry: The Role of Organic Chemistry in Drug Research (1993)  
  Gay, Peter Freud: A Life for Our Time (1988)  
  Gellner, Ernest The Psychoanalytic Movement (1985)  
  Gillon, Raanan Philosophical Medical Ethics (1986)  
  Goldman, Martin Lister Ward (1987)  
  Goodwin, Frederick K. and Jamison, Kay Redfield Manic-Depressive Illness (1990)  
  Gordon, Richard A. Anorexia and Bulimia (1990)  
  Grunbaum, Adolf The Foundations of Psychoanalysis (1984)  
  Guyton, A. C. Human Physiology and Mechanism of Disease (1992)  
  Harris, Seale Banting's Miracle (1946)  
  Holtzmann Kevles, Bettyann Naked to the Bone (1996)  
  Jaspers, Karl General Psychopathology (1946)  
  Kellock, Brian The Fibre Man, the Life Story of Dr Denis Burkitt (1985)  
  Kinoy, Barbara (ed.) Eating Disorders: New Directions in Treatment and Recovery (1994)  
  Knight, David Robert Koch: Father of Bacteriology (1961)  
  Le Fanu, James (ed.) Preventionitis: The Exaggerated Claims of Health Promotion (1994)  
  Leone, Daniel A. The Spread of AIDS (1997)  
  Levine, Israel The Discoverer of Insulin (1959)  
  MacFarlane, Gwyn Alexander Fleming (1985)  
  Maxcy, Kenneth Fuller, Rosenau, Milton Joseph, Last, John M., Wallace, Robert B. Public Health and Preventative Medicine (1992)  
  McKenna, P. J. Schizophrenia and Related Syndromes (1994)  
  Nicolle, J. Louis Pasteur: The Story of His Major Discoveries (1961)  
  Phillips, Jonathan The Biology of Disease (1995)  
  Pinker, Steven How the Mind Works (1998)  
  Reid, Robert Microbes and Men (1975)  
  Rowland, John The Penicillin Man (1957)  
  Rowland, John The Insulin Man (1966)  
  Rycroft, Charles Anxiety and Neurosis (1968)  
  Ryle, J. A. The Natural History of Disease (1988)  
  Sournia, Jean-Charles The Illustrated History of Medicine (1992)  
  Sulloway, Frank J. Freud: Biologist of the Mind (1979)